ssd questions

[joecool]

So i'm building a new rig, it'll be AMD based, haven't settled on the core yet but either a PhenomII x2 black (and hopefully get a free core or two!), or an AthlonII x4, paired w/4GB of RAM. I'll be running Win7-64. Initially I was just gonna get a plain old SATAII HD, but now am starting to consider and SDD drive. I always keep the OS/programs on a drive separate from my data so I'm thinking I could get buy w/a 64GB SDD, which is as much as I would want to spend. Here's my questions:

1) Is the performance of SDD drives that much better? Do they maintain their performance advantage over time as the drive gets written many times? Reading articles around the web it sounds like performance degrades as the drives become fragmented w/random writes and deleted data.

2) Is there anything you can/should do to maintain SDD performance? Does defragging still make sense?

3) I run BootitNG, a really spiffy partition manager and boot loader, and usually have multiple OSes available to run. With a 64GB SDD drive I would still want to maintain two partitions, a bigger one (maybe 50GB?) for Win7, and a smaller one (say 10GB) for WinXP for legacy apps and external devices. Is this possible w/SDD drives - in other words, can you partition them, etc, just like you do an HD?

Thanks in advance,

Joe

 

[Zap]

1) Yes, SSD performance is really that much better. However, it does depend on what you are doing with it. Windows sees a good benefit, so that's why SSD "boot drives" (cheap 30-40GB) are popular. Beyond that, some apps see a benefit and some do not. In a desktop computer the cost effective method is to get an SSD for Windows and critical apps, and then a normal HDD for data and other stuff.

2) Do not ever defrag an SSD. What does defrag do? It puts file fragments closer to each other so as to not incur a performance penalty from HDD seeking. Well, SSD seeks are pretty much instantaneous, so I don't see how it can make things faster. OTOH it just adds more wear/tear to the SSD whenever you defrag. To maintain performance, you will want to use an SSD that supports TRIM and Windows 7. Alternately, use an SSD that the manufacturer supplies a maintenance utility for. Oh yeah, also do not fill up an SSD. Exact numbers may vary, but rule-of-thumb is to not fill up the SSD past around 80% or so, as performance often drops when the SSD becomes filled.

3) Yes, they can be partitioned.

 

[joecool]

great, thanks for the info. sounds like a 64gb ssd is the way to go. can't wait to see how much faster it really is!

just curious, what is the life expectancy of these things?

 

[FishAk]

I agree with Zap with one cravat.

It is my view, that an SSD using a SandForce controller CAN be filled to capacity without loosing performance. The difference between SF and other controllers, is that SF compresses the data it writes- saving space on the drive other controllers don't save. It is my view that SF most likely uses this saved space as spare area, negating the need to provide additional empty space to maintain performance.

 

[joecool]

well, since i never fill up an hd anyway, i'm not that concerned w/that. i always try to keep around 25% of the disk free, and size my partitions accordingly. again, i'm thinking a 50gb partition for win7 should be plenty, and 10gb for winxp since it will have very few apps. if i had to i could even devote then entire sd drive to win7 and put my xp partition on an hd. actually, i think i will do that since i won't use the xp partition that often so performance won't matter as much.

 

[sub.mesa]

Note that you should take care to have 'aligned partitions'. Windows 7 and Vista create partitions with an aligned offset which is 1MB or 2048 sectors of 512 bytes; Windows XP on the other hand creates misaligned partitions starting at 31.5 Kilobytes or 63 sectors. This creates performance problems on most RAID arrays and also SSDs without RAID.

So either use Windows 7 to create the partitions for you, installing the boot loader afterwards, or use an alternative method to create the partitions but check for alignment afterwards.

How to check alignment? Simply download AS SSD (google on it) and run it on your SSD, then it should say .. KB - GOOD or .. KB - BAD. That instantly tells you whether your partition is aligned (good) or misaligned (bad).

 

[joecool]

a friend mentioned that writes on these things are really slow - is an sdd slower for writes than an HD? if so, should you put the page file, internet cache, etc etc on an hd? what's the right way to maximize the performance of these things?

 

[Zap]

I agree with Zap with one cravat.

LOL, there's a big difference between a cravat and a caveat.

a friend mentioned that writes on these things are really slow - is an sdd slower for writes than an HD? if so, should you put the page file, internet cache, etc etc on an hd? what's the right way to maximize the performance of these things?

Some of the SSDs write slower than HDDs, however still "feel" faster due to the low access times. If you are really concerned with write speed, then get a Sandforce controller drive. I think the Intel drives and the new Jmicron/Toshiba controller drives are the ones with slower writes.

 

[joecool]

I'm looking at this drive: http://www.newegg.com/Product/Produc...82E16820139132

Any thoughts?

 

[FishAk]

a friend mentioned that writes on these things are really slow - is an sdd slower for writes than an HD? if so, should you put the page file, internet cache, etc etc on an hd? what's the right way to maximize the performance of these things?

Nothing with an Indilinix, Inte,l Bearfoot, or SandForce controller will be slower than a HDD- even with sequential writes- where they come the closest.

Paging, and caching, is typically small files, where the SSD really shines. Because of it's low (almost non-existent) seek time, a modern SSD is more than a hundred times faster than a HDD with small files.

 

[FishAk]

LOL, there's a big difference between a cravat and a caveat.

Good catch there, Zap!

 

[joecool]

i like to wear a cravat

 

[FishAk]

I'm looking at this drive: http://www.newegg.com/Product/Produc...82E16820139132

Any thoughts?

I believe that drive has a Tosheba/JMicron controller. I would not recommend it at that price. You can get an OCZ Vertex 2 for about $20 more. I don't think it will loose it's performance even when filled to capacity. The Kingston... not so much.

 

[joecool]

note the kingston is $100 after mir. the nearest thing i can find in the vertex 2 series is this: http://www.newegg.com/Product/Produc...82E16820227550 which is only 60gb and $135 after mir. consumer reviews are about the same for each - high 70% 5 eggs. seems like i should go w/the cheaper drive.

 

[FishAk]

The difference is spare aria.

An SSD needs unused nand to prevent excessive write amplification, and to keep performance up. Both drives have 64Gb of nand flash, and both reserve 7 percent for the controller to use. However, over the long haul, most people agree a drive needs 20 to 30 percent set aside to maintain performance. Better controllers can do better with less empty space.

SandForce is the only controller to compress data when it writes to the nand. However, it doesn't report this saved space to the operating system. In this manner, it ends up with a very significant amount of empty nand that only the controller knows about.

It is my view that SF uses this saved space to supplement the 7 percent default reserved nand. Because of this, a user can fill the full 60Gb with no penalty.

When you consider the actual usable space of the various drives, the price/Gb becomes much closer together. Add to that the significant speed advantage of the Vertec 2, and you'll see, it's well worth the small premium over the competition- if there is a premium.