Vista 64 and SuperFetch

[Alash]

Been reading up a little about RAM, the role it plays in a complete system, and how the market looks. Tom's article pretty much sums up the answer to the last bit*, but I'm still not too sure about the role and importance of RAM. As the prices are ridiculously low I therefore thought to check it out myself and go for the full Monty: 8GB of DDR2-800 in 4 modules. My system is a Vista Ultimate 64-bit SP1, which, I'm told, supports up to 128GB (leaves a considerable margin for later experiments), and with its SuperFetch function more RAM is always welcome as it (supposedly) speeds up loading of frequently used applications. What I'm more uncertain about though, is the rumors I heard - and haven't been able to confirm/deny - that Vista (if fed with 8GB) automatically allocates 4GB for the OS and 4GB for applications. And more interestingly, how does this SuperFetch work with less 'normal' applications such as computer games. If the extra 4GB (read: $80) makes SuperFetch cache the games I tend to play I believe a lot of time could be saved in the loading processes, making the 8GB less of a deadweight and a useless voltage consumer. Or maybe I'm completely missing something?

*For those who haven't yet read it and can't be arsed to, the author throws about 20 benchmarks at anything from DDR2-677 to DDR3-1333 using a mixture of the older P4 Extreme CPU and a newer E8400. The point proven is that performance between the best and worst (cheapest and most expensive) of these models vary on average by 6%, at most. Following that conclusion the cheapest pair of stable DDR2-800 modules is pretty much the perfect fit for anyone but the wildly enthusiastic power-clocker who wants to throw mountains of money at no apparent performance gain (...puts on flame coat).

 

[Nothinman]

What I'm more uncertain about though, is the rumors I heard - and haven't been able to confirm/deny - that Vista (if fed with 8GB) automatically allocates 4GB for the OS and 4GB for applications.

No, any time you hear about a hard split in memory amounts the person is almost always talking about virtual memory and not physical memory. Because the VM numbers are so high for AMD64 (256TB) that the fact that a split exists is a moot point. If you're running a 32-bit OS 4G total VM still matters, but that's not the case for you so 64-bit applications have pretty much infinite virtual memory and whatever physical memory is available. For 32-bit processes it's different because they're still limited to 4G total. Now that the OS doesn't have to share that 4G the process can really have it all but MS only does that for binaries that are marked LargeAddressAware, all other binaries will only get 2G of VM.

And more interestingly, how does this SuperFetch work with less 'normal' applications such as computer games. If the extra 4GB (read: $80) makes SuperFetch cache the games I tend to play I believe a lot of time could be saved in the loading processes, making the 8GB less of a deadweight and a useless voltage consumer. Or maybe I'm completely missing something?

That's the idea and since the cache that SuperFetch fills up isn't tied to a single process the above 2G or 4G limitations for 32-bit apps doesn't apply to what SuperFetch can cache.

 

[Alash]

Wow, those were great answers - thanks a lot!

The games in mention will supposedly 'support 64-bit processes', so - depending on what you put into the term 'support' - SuperFetch should be able to cache them. Do we know how much this caching process means for loading times though? Just how super is this SuperFetch? As far as I can tell the answer to that is the only thing that would make me buy an additional 4GB of RAM; or are there other potential advantages of bigger memory capacity?

 

[Nothinman]

The games in mention will supposedly 'support 64-bit processes', so - depending on what you put into the term 'support' -

Well a process is either 64-bit or not, there's no half-way mark.

SuperFetch should be able to cache them. Do we know how much this caching process means for loading times though? Just how super is this SuperFetch?

There's a lot of variables, SuperFetch is essentially just a service that monitors usage and precaches things into memory that it thinks you're going to want to use soon. If it decides to cache what you want to use the difference will be that of reading the data from memory instead of the hard disk, if not then you fall back to the hard disk as if SuperFetch wasn't there.

 

[cmdrdredd]

The short answer for me would be, if I can get 8GB then I will get 8GB.

 

[Alash]

There's a lot of variables, SuperFetch is essentially just a service that monitors usage and precaches things into memory that it thinks you're going to want to use soon. If it decides to cache what you want to use the difference will be that of reading the data from memory instead of the hard disk, if not then you fall back to the hard disk as if SuperFetch wasn't there.

So the question is how much time it will take to read the data from an average hard drive, and how good this SuperFetch is at 'guessing' the right applications. Maybe I've gotten this all wrong, but the guessing process seems much similar to that of the L2 cache?

SuperFetch aside, why should I (or should I not) upgrade from 4GB to 8GB on a Vista 64 OS with standard'ish application usage?

 

[Nothinman]

So the question is how much time it will take to read the data from an average hard drive, and how good this SuperFetch is at 'guessing' the right applications. Maybe I've gotten this all wrong, but the guessing process seems much similar to that of the L2 cache?

No, L2 cache on a CPU just holds whatever was stored there until it's replaced without any logic behind it at all.

 

[Acanthus]

Originally posted by: Alash

There's a lot of variables, SuperFetch is essentially just a service that monitors usage and precaches things into memory that it thinks you're going to want to use soon. If it decides to cache what you want to use the difference will be that of reading the data from memory instead of the hard disk, if not then you fall back to the hard disk as if SuperFetch wasn't there.

So the question is how much time it will take to read the data from an average hard drive, and how good this SuperFetch is at 'guessing' the right applications. Maybe I've gotten this all wrong, but the guessing process seems much similar to that of the L2 cache?

SuperFetch aside, why should I (or should I not) upgrade from 4GB to 8GB on a Vista 64 OS with standard'ish application usage?

Superfetch is blind to application usage, it attually uses simple file indexing and load counts to determine what to cache.

It wont load "Doom3" but if it sees doom3.exe and a ton of other doom related files being loaded frequently, superfetch will begin caching them in advance.

Also note that superfetch will not work immediatly as it needs to establish what is being used frequently, give it a good couple of days to make the determination if its helping or not.

 

[Alash]

The speed and quality of replies on these boards is astonishing!

@ Nothinman - what mechanicm/logic determines what to store then? If you tell me it's a miniature hamster rolling dices I'll have to dedicate my life to hardware...
@ Acanthus - once established, is there anything that determines which Doom 3 files to cache or does it just cache as many as I have room for in my memory modules? And if the latter is the case, surely 8GB is worth the equivalent of 6 BigMac menu's?

 

[chizow]

Originally posted by: Alash
Wow, those were great answers - thanks a lot!

The games in mention will supposedly 'support 64-bit processes', so - depending on what you put into the term 'support' - SuperFetch should be able to cache them. Do we know how much this caching process means for loading times though? Just how super is this SuperFetch? As far as I can tell the answer to that is the only thing that would make me buy an additional 4GB of RAM; or are there other potential advantages of bigger memory capacity?

Just to clarify, games do not need to be 64-bit in a 64-bit OS in order to fully benefit from SuperFetch as it is part of the OS. Ideally, games are native 64-bit or at the very least, /largeaddressaware so that they can use more RAM without needing SuperFetch's guessing and caching. The more RAM the application uses, the less is needed for SuperFetch to cache up to the combined maximum benefit of the game's total size. SuperFetch essentially works as a buffer so that there is less need to access the HDD and the difference between HDD and RAM is pretty extreme, but its still best if the application itself directly addresses the memory it needs.

As for how well it works, you'll see many comment that their applications and games tend to launch instantaneously. In games typically the benefit will be most realized on zone transitions and load times, although it might take a reload or a second visit to an area to see the full benefit. It does take about 3-4 days for SuperFetch to get a good idea of what to cache, but its pretty obvious when it does as you'll see all your free RAM become cached within minutes of a reboot, whereas you might see 3-4GB sitting unused and Free when you first install.

 

[Alash]

So if I understand you correctly SF has quite a profound impact on transitions within an application or between applications, granted that there is a degree of frequency/repetition in the your computer usage. Is the file index stored indefinitely or does it refresh/reset? I.e. if I have loaded that in-game zone before, will it remember for all eternity, or will it reset as soon as I quit the application, reboot the PC, after a specific time interval etc.?

Also, how important do you reckon the presence of SF is on choice of RAM? Vista I'm told use about 0.5 GB more than XP does, but aside from that will an increase in capacity affect SF noticeably? And for an application such as Doom 3, roughly how much memory is needed to fully cache the game? I realize this is a fairly loose question, but as an estimate how does it scale?

 

[chizow]

Originally posted by: Alash
So if I understand you correctly SF has quite a profound impact on transitions within an application or between applications, granted that there is a degree of frequency/repetition in the your computer usage. Is the file index stored indefinitely or does it refresh/reset? I.e. if I have loaded that in-game zone before, will it remember for all eternity, or will it reset as soon as I quit the application, reboot the PC, after a specific time interval etc.?

I'm not completely sure how SuperFetch determines what to cache and when. Most descriptions make it seem very simple, determining cache by simple file system info, like date modified/accessed and directory structure etc. I'm sure there is some kind of file index that keeps track of what was accessed and when, maybe the page file itself. It probably has a static size (larger than your total RAM) so that it doesn't get unwieldy and constantly overwrites itself with what should be cached. If you reboot, the cache will be quickly repopulated with previous file index info. Again, I'm not sure how SF works, but if I were to design it I'd have it cache up the loading files of multiple apps for faster start-up. Once an app is launched, gradually swap out the unused start-up files and begin caching files in that folder and replacing data that doesn't relate to the launched app.

Also, how important do you reckon the presence of SF is on choice of RAM? Vista I'm told use about 0.5 GB more than XP does, but aside from that will an increase in capacity affect SF noticeably? And for an application such as Doom 3, roughly how much memory is needed to fully cache the game? I realize this is a fairly loose question, but as an estimate how does it scale?

I'd say your original linked review and assessment is accurate; you're better off with more DDR2 800 than less DDR2 1000+ with Vista 64 and SuperFetch. When you see people say "Vista will use all your RAM" they're referring to SuperFetch precaching data up to the physical RAM limits in your machine, so yes an increase in capacity will affect SF. Another consideration is HDD speed and noise. You'll still see a lot of HDD activity, and possibly even more with all of Vista's search indexing and SF functions so I'd definitely go for quieter HDDs if noise bothers you. Any of the newer 750GB/1TB 7200RPM drives should give you a nice balance of performance, acoustics and capacity.

For Doom 3, I'm not sure what the total size of the game is but its probably not that big given its an FPS and an older title. So say its 3-4GB and 32-bit app that is not /largeaddressaware flagged. That means the app itself will be limited to ~2GB of addressable memory, meaning you still have 1-2GB that will need to be swapped at some point. Typically, FPS do not usually suffer as bad from insufficient memory, as the different textures and sound assets are loaded between map changes or cut-scenes and swapped on a wholesale basis. But if you played Doom3 a lot or SuperFetch knew to cache that other 1-2GB as soon as you launched Doom3.exe, that load would be as fast as a transfer from memory instead of the long chugging delay that occurs when loading from HDD. Still, a load from say, the 5th level to the 1st level should be much faster compared to the first load for any given level.

 

[Alash]

Once again a great reply. The game I'm planning on sacrificing my social life on is Age of Conan, which - being an MMOG - should work a little differently than Doom 3. Ultimately it's a much larger world than what FPS, RTS and other genres offer, and as such there should be more to load (depending on how Funcom have opted to split Hyboria into zones or instances); or maybe just more to calculate? My guts tells me a MMOG will make more use of RAM capacity and therefore SF, but I've been wrong before.

More over the inflamed XP vs. Vista debate: how does a 4GB XP 32-bit setup compare to a 8GB Vista 64-bit (with SF) in terms of loading times? I'm prone to stick with Vista as it is, but it would be good to know the differences at any rate.

As sort of an off-topic I've been warned about mainboard being unstable with 4 modules plugged in. How much am I expected to suffer from this? I'm buying a ASUS P5N32-E SLI, nForce 680i SLI mainboard which should be fairly modern, but I'm less of a gambler when it comes to hardware so I'd like to be sure the ah heck doesn't complain too much.

 

[n7]

I run 8 GB & don't see myself going lower for my main system ever again.

Do i need that much?
No.

But with DDR2 so cheap (& it won't be for much longer), i got that much basically because of the price.

I find Vista feels snappier overall than XP for most stuff, which is likely due at least somewhat to Superfetch.

That said, i also don't think you'll find a large difference between 4 GB or 8 GB right now unless you do a lot of photo/video editting, or run virtual OSes.

But it's certainly nice to be able to run a silly amount of things simultaneously w/o ever having to get even dreaming about ever running low on RAM.

Another thing to keep in mind is that Vista does tend to scale its RAM usage based on how much RAM is installed.
I still don't know how it determines things, but you'll see a lot more RAM usage at idle on a system w/ 4+ GB in Vista than on one with 2 GB, or certainly 1 GB.

I'd say that 4 GB is certainly adequate for current use for most people in Vista, but you can get quite close to using that all up, hence why having 6 GB or 8 GB becomes nice.

As for four dimms, you'll likely be okay...just be aware overclocking with four dimms - i mean OCing the RAM specifically - can be MUCH harder.
I've managed a decent OC i'm happy with for my 8 GB (DDR2-1050 5-5-5-18), but i'd also say it can be a nightmare.

If you're running a more conservative overclock, or are keeping the RAM at a lower speed, it's not usually so bad.

 

[Acanthus]

Originally posted by: n7


That said, i also don't think you'll find a large difference between 4 GB or 8 GB right now unless you do a lot of photo/video editting, or run virtual OSes.

But it's certainly nice to be able to run a silly amount of things simultaneously w/o ever having to get even dreaming about ever running low on RAM.

Until you try to copy a DVD with nero.

That pile of crap actually writes a 4.7GB image directly to ram....

 

[skypine27]

I too run 8 GB of ram in Vista Ultimate 64.

After going from 4 to 8, I did not notice any difference in system performance and gaming. It worked fine with 4, and continued to work fine with 8.

I think it's mostly a "feel good thing". I feel better about Vista w/ 8 GB than I did with 4.

I'm sure by the time I part out my current system on Ebay mid next year and build a new one, they'll have 4GB dimms out and I'll be putting in 16GB. Again, just for a feel good thing.

 

[Ratman6161]

I'm running 8 GB for two reasons:

1. I do a lot of work with VMWare Workstation and often have two or more virtual machines running in the background. They perform a lot better when they have plenty of ram and also if you run them on a different physical hard drive than the host operating system.

2. As others have mentioned, DDR2 is cheap. My Gskill DDR2800 was $79 for a 2x2 pair, so I bougt two pairs.

However....most of the machines I work with that use vista run just fine for most purposes with a total of 2GB. For games you might want to go with 3GB because then the game can take the full 2gb user space and still have 1GB left for the OS and background tasks. But unless you are running a bunch of stuff in the background while gaming, I don't see how more than that will help you.

The discussion on pre-fetch is interesting, but I'm in doubt as to weather it really has anything to do with actual game play. When somthing is already in the prefetch memory, it will load faster so the game would load faster than it would if it had to read it from the disk. But once loaded, I would think it would have nothing to do with the actual play of the game??? Just speculation.

 

[Alash]

I'm thinking that SF shines in any situation where data has to be loaded from the hard drive, and while that for games is mainly when starting the application, these days I find most games have separated their world into zones that each require loading time; and even more so if you move on to the MMOG genre. Unless I've misunderstood something SF will help me as I play as well - not in the sense of improving FPS, but by making the necessary in-game transitions happen faster. It's a gaming experience thing I guess.

The question remains though, to which extent the effects of SF are noticeable in modern systems. At this point for me it's sort of like praying: I don't believe in it, but nothing is lost doing it. I don't believe 8GB will bring substantial improvements to my system, but I choose it over an order of 6 BigMac menu's because, well, I'm better off without the extra fat. And maybe it'll if I'm lucky it'll give me an edge in stressed environments (that is: the lack of fat, as well as the extra RAM)...

 

[chizow]

Originally posted by: Alash
Once again a great reply. The game I'm planning on sacrificing my social life on is Age of Conan, which - being an MMOG - should work a little differently than Doom 3. Ultimately it's a much larger world than what FPS, RTS and other genres offer, and as such there should be more to load (depending on how Funcom have opted to split Hyboria into zones or instances); or maybe just more to calculate? My guts tells me a MMOG will make more use of RAM capacity and therefore SF, but I've been wrong before.

More over the inflamed XP vs. Vista debate: how does a 4GB XP 32-bit setup compare to a 8GB Vista 64-bit (with SF) in terms of loading times? I'm prone to stick with Vista as it is, but it would be good to know the differences at any rate.

As sort of an off-topic I've been warned about mainboard being unstable with 4 modules plugged in. How much am I expected to suffer from this? I'm buying a ASUS P5N32-E SLI, nForce 680i SLI mainboard which should be fairly modern, but I'm less of a gambler when it comes to hardware so I'd like to be sure the ah heck doesn't complain too much.

AoC is still under pretty heavily enforced NDA, but a similar MMO in terms of both visuals and system performance would be LOTRO. LOTRO is one of the games that I guessed would be able to take advantage of more RAM and was a big part of my decision to upgrade to Vista 64.

When LOTRO first released, the client was extremely prone to crashing, stuttering and thrashing in both Vista and XP, particularly in specific zones like busy towns such as Bree. With the Helegrod patch (June/July) and the Vista Hot Fix, crashing was fixed for the most part, but stuttering/thrashing still remained. The Helegrod patch also enabled /largeaddressaware for 64-bit OS and greatly reduced the amount of stuttering and thrashing for systems with 4GB or more RAM.

You've already commented on some of the aspects of MMOs that would benefit from more RAM. The one thing I've noticed for sure is that MMOs tend to have larger zones to begin with, required more detailed and varying textures to span the zone compared to your typical FPS or even RPG title. Another thing in an MMO is the dynamic and random nature of the game makes it more difficult for the client/server to effectively "guess" what assets will be needed. This was a major reason for the Bree performance issues, where you'd come across a vast array of different textures, art assets, and sound due to the wide assortment of equipment and player characters. Having more RAM simply means the client can directly cache or Vista can precache more of those assets, and keep them stored in memory instead of having to constantly flush and re-cache them.

In terms of direct performance differences, its very difficult to gauge, especially since reviews comparing XP to Vista will not typically include the relevant benchmarks, like load time differences. The problem with most comparisons is that they conduct the benchmarks like your typical Graphics/FPS review instead of a Storage review. Personally I have noticed quite a bit of difference, although it may take a reload or revisit of a place to see that benefit. Some examples would be in LOTRO, zoning via Hunter port or even changing characters. You might see some load time the first time, but zoning should be near-instant on subsequent transitions. Even moving around you should see much less stuttering/throttling accompanied by HDD thrashing (can check page/hard fault activity) and texture/object "popping". At the very least you'll see less of it after the first run through as objects and assets remain in memory.

Potential problems with 4 dimms and 4GB+ are hit and miss. Most of the OS and software quirks have been worked out (myriad Vista 4GB hot fixes, X-Fi fixes, etc), but how your board handles 4 dimms still seems to be hit or miss. On my board, I had to flash the BIOS to get 4GB to operate properly only to run into other problems with 4GB installed. Most of the major issues were fixed for me by November and although it wasn't a flawless transition to 4GB+ and 64-bit, it wasn't anything I didn't expect and has definitely been worth it.

 

[Scotteq]

My experience with Vista 64 and RAM is this:

(1) 1GB - Ummm... It runs... I guess...

(2) From 1 to 2 GB - Thank you for sprinkling holy water on my computer, God!

(3) From 2GB to 4GB - Seemed to be snappier than before

(4) From 4GB to 8GB - I have to look at the display to notice the difference.


YMMV - I game, but don't any heavy rendering or video.

 

[Alash]

Alright the issue of capacity and model is now - thanks to you - somewhat resolved. What remains is the issue of brand and what that means to pricing. With my current motherboard I am able to overclock CPU without worrying about it affecting RAM, so what I'm looking for is 4 2GB DDR2-800 (PC6400) modules that run stable at stock specs, and that will use all four slots without complaints.


Transcend modules sell for $133.98, and have received good reviews from Newegg customers.
G.SKILL modules sell for $149.98, and have received excellent reviews from Newegg customers.
Patriot Viper modules sell for $189.98, runs at 4-4-4-12 timings and have received a few good reviews from Newegg customers.

Which one do you reckon I should go for, and why?

 

[Scotteq]

No direct experience, but of the ones you mentioned I would pick the Patriot stuff - Nice timings.

Perhaps it's just familiarity, but for memory I almost always buy OCZ or Corsair. Generally a little more expensive, but their support seems to be a cut above what some of the other guys do. OCZ in particular have fast/responsive people working their discussion boards. Both support responsible levels of overclocking as well, which is also quite nice.


When you do this, please remember that makers (both Mobo and RAM) often presume a 2 DIMM setup, and their timings/voltages are developed with that in mind. Therefore, when you double up these may or may not be adequate. So you potentially could end up having to play with it to get it all to work.

I recommend manually set all timings to the manufacturer's certified. Manually set tRFC to 54 or greater, and ensure the command rate is set to 2T.

If there's an issue, then manually set the voltages to the max (or near max) of the manufacturer's rating for the modules you have installed. Should be 2.1v~ish. If that works, stress test, then consider dropping a 10th at a time. Slightest sign on instability, bump it back a 10th. Do Not Over Volt your RAM.

If that doesn't work, the next step would be to bump the voltage to the North Bridge by one setting, and try again. So if the NB voltage is 1.3 then bump it to 1.31, or whatever the next higher setting is.

If that still doesn't work, then relax your timings a notch: For example, if your RAM is 4-4-4-12, then change to 5-5-5-15. Try again.

It's possible you'd need to try a couple combinations. But from what I've seen, on quality components, you're looking at a 10th or 100th of a volt here, and a tweak there. You should not need to make big changes, rather small ones to find a working setup.

In my case, I have 8GB of 800 Mhz OCZ Reapers 12 hours Prime 95 Blend stable at 4-4-4-12, 2T, 2.05volts. tRFC is 54. FSB is set to 1.33. There was no need to loosen timings on my setup. Rig details in siggy


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