Utilising 1 SSD as both OS + normal drive and Intel SRT cache

[Aotengs]

Hi guys,

This is my first time posting here but through my many google searches looking for information on my first build I will be doing soon, I always seem to get led to topics here which always seem to have fantastic responses .

Anyway, I have a Samsung 840 120gb SSD. I read somewhere about Intel's Smart Response Technology caching system and read further about a fellow from here who also managed to utilise his SSD as both that 60gb cache and the remaining as a standard OS boot drive + normal SSD functions.

My question was: would doing this harm the lifespan of the SSD by a noticeable amount? I think that the lifespan of a SSD is determined by how much data it writes, the review here for the Samsung 840 rates the lifespan at 3.5 years assuming 10gb of read/write per day with usage as a normal drive; would having further functionality as a SRT cache further increase how much data it reads/writes and therefore lower its life expectancy? (And by how much?)

My friend also told me that the speed of a SSD is limited by the amount of IOPS it can do, would having the drive split into two partitions as both a drive and a cache split the amount of IOPS therefore reducing performance for both the drive and the cache itself? What kind of performance losses would there be?

Sorry this post is pretty long, I guess I am just after what the possible cons are of setting up a SSD as both a boot drive and a cache

Thanks very much for any info guys!

 

[milee]

It depends on how much data you use frequently that would benefit of caching and how intensive your workloads are.

If for example you got ~60GB of data that you READ frequently you should just move it to the SSD and access it as much as you need.

If you have to WRITE that much data, then it's a matter of how often and how fast you need to write it. I would probably use a dedicated SLC SSD in this case (Intel 313 for example).

 

[Smoblikat]

Hi guys,

This is my first time posting here but through my many google searches looking for information on my first build I will be doing soon, I always seem to get led to topics here which always seem to have fantastic responses .

Anyway, I have a Samsung 840 120gb SSD. I read somewhere about Intel's Smart Response Technology caching system and read further about a fellow from here who also managed to utilise his SSD as both that 60gb cache and the remaining as a standard OS boot drive + normal SSD functions.

My question was: would doing this harm the lifespan of the SSD by a noticeable amount? I think that the lifespan of a SSD is determined by how much data it writes, the review here for the Samsung 840 rates the lifespan at 3.5 years assuming 10gb of read/write per day with usage as a normal drive; would having further functionality as a SRT cache further increase how much data it reads/writes and therefore lower its life expectancy? (And by how much?)

My friend also told me that the speed of a SSD is limited by the amount of IOPS it can do, would having the drive split into two partitions as both a drive and a cache split the amount of IOPS therefore reducing performance for both the drive and the cache itself? What kind of performance losses would there be?

Sorry this post is pretty long, I guess I am just after what the possible cons are of setting up a SSD as both a boot drive and a cache

Thanks very much for any info guys!

I dont it would do anything to add a cache to your OS on the same drive. For many reasons, which I will list:
1.) A cache is a small area of very fast storage. If the cache and things that are being cached are on the same disk, it would have less performance than having no cache at all. Since the information would be on different partitions and you would have to use extra software to access it, rather than just running it from the single disk.
2.) Your OS already uses the SSD as a "cache"......page file. Windows by default adds a pagefile that is as large as the amount of RAM you have installed in the system, so that already acts as a type of cache.
3.) SSD's are fast enough, and RAM also acts as a sort of cache, though not as permanent. You wont really notice a difference in speed when using an SSD + an SSD cache, vs just an SSD. And your RAM will take care of everything else (while you are actively using the program).


I hope I answered your question.

 

[milee]

@smoblikat The caching layer in SRT is used for mechanical storage. To cache the OS which resides on the same SSD would be absurd.

 

[Cerb]

My question was: would doing this harm the lifespan of the SSD by a noticeable amount? I think that the lifespan of a SSD is determined by how much data it writes, the review here for the Samsung 840 rates the lifespan at 3.5 years assuming 10gb of read/write per day with usage as a normal drive; would having further functionality as a SRT cache further increase how much data it reads/writes and therefore lower its life expectancy? (And by how much?)

It would, but how much would depend on your usage. However, those 10GB writes per day were also assuming 10x WA. I don't think I've yet seen a report of even 2x for the 840, over time, with actual use, which would make it more like 17 years.

My friend also told me that the speed of a SSD is limited by the amount of IOPS it can do, would having the drive split into two partitions as both a drive and a cache split the amount of IOPS therefore reducing performance for both the drive and the cache itself? What kind of performance losses would there be?

IOPS (input/output operations per second) are a description of speed, used for SSDs because they make for bigger numbers than MBps, and because HDDs can barely go over 200 at their best. It's not statically split, though. If you are reading data from the HDD volume that's in the SRT cache, or writing to the SRT cache, that gets all the speed of the SSD. If you are accessing data just in the OS volume, that gets the full speed, too. You get sharing when both are being accessed at the same time. Other SSDs may be faster in such that scenario than the Samsung 840, but the 840 will still be many times faster than your HDD.

It's a case where if you were planning to buy an SSD with this use in mind, the 840 120GB probably wouldn't be the one you'd want to get; but already having one, it will still going to be an improvement over the HDD alone, if you want to use it this way (especially with someone having figured out the logistics of using a single SSD as both cache and main OS volume at the same time).

The main cons will be slightly lower peak SSD-only performance, less space for your OS+apps, and probably a bit worse long-term write performance, on account of all the random writing to the SRT partition.

TBH, though, unless you are waiting on writes to the HDD that really can't be just moved to the SSD, or the same for many small files, I'm not sure it would be worth the trouble. SRT is one of those things that makes the most sense in (a) notebooks and (b) for people aren't tech-savvy, though with a few other scattered niches.

 

[Smoblikat]

@smoblikat The caching layer in SRT is used for mechanical storage. To cache the OS which resides on the same SSD would be absurd.

Exactly, thats why I was confused at why OP wanted to do that.

 

[Aotengs]

Hey thanks for the responses guys.

Smoblikat, what I meant was that I would have the OS loaded on the SSD and at the same time have half of the SSD used as a cache for a mechanical drive and my various apps, files etc on there (not the OS).

The theory is that I would put up with a sacrifice in some pure SSD performance for the benefit of the SRT software to automate the whole process of the boosting of performance that comes with a SSD, but applicable to an entire HDD worth of files. But, since I have the OS purely on the SSD, the OS would get the full benefit of the SSD.

milee, I'm not sure how much data I will likely be using on a frequent basis, that's why I'm looking to utilise this caching system - so in case every couple of days I find myself using various programs that very often I won't have to plan beforehand or guess how much I will be using those programs to put them on the SSD or move anything at all which would be a little more convenient.

My only hope is that this won't stress out my SSD too much to have two partitions used in this way haha

 

[rangerevo8]

Hi Aotengs,

So did you ended up configure the SSD for OS + Intel SRT Caching for HDD two years ago? Was curious if it was working @@

 

[tweakboy]

Im sure it works, just a little buggy. Reboot pc if you have to,, sort this out.. gl