seeking SSD speed clarification
#1
I have questions about SSD's.

When I read their specs, they only mention whether they are SATA II or III and they mention the maximum read/write speeds.

But they are "maximum" read/write speeds and they mostly matter when you're copying a large file to or from the SSD (sequential). But since we are using it in an htpc environment where the media is stored on HDD or NAS, the maximum speed only matters when we install the OS the first time (When it copies all the files)


I remember a while back I was reading that "random access" speed is what matters the most for xbmc because it is used when the skin loads all the thumbs and fanart, etc, that are all stored on different areas on the SSD as individual files, so it affects xbmc gui speed significantly. Obviously the random access speed to a bunch of individual files would be much much slower than the maximum sequential read speed (Just compare your copy speeds in windows between copying a single 300MB file and a 300MB folder with 100,000 files in it). And an SSD with a 180MB/s max read speed could technically be much faster at random access compared to an SSD with 500MB/s max read speed.

I was reading that the random access speed depended on the quality of the controller.

The problem is, when I am shopping around for an SSD, what spec should I be looking at to get an idea of their random access speed??

I guess this is the reason why some SSD drives get comments such as "It was really fast when I first started using it, but now it is as slow as my HDD". Because when they first got it, they used it to copy all their files and OS onto it, and it was fast due to its high max sequential read/write, but then when they started using it for xbmc or other software, where random access mattered and the drive just didn't deliver on that front.

That article also talked about how the intel x-25 had much lower max read/write speeds compared to other SSDs but it was actually much faster than most at random access, that's why they were more expensive. What about OCZ, Kingston and Crucial drives? How do I compare them?

Thanks in advance.
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#2
I understand where you are coming from, however you are talking about a HTPC? It's very easy to spend to much on a HTPC (overkill) unless you have a particular reason for doing so, or you don't mind spending the money because it has more value to you.

Under most circumstances the slowest SSD is still faster than a spinner.

To get maximum performance from a SSD, do not copy or clone your current system. Do a fresh install and keep a current back up. You only use it for your Operating System, files stored on a different disk. You really don't need a large disk, 30GB is usually enough for Win7 if you install it properly, 64GB is nice if you want to dual boot.

Everyone is different, but the reason I like SSD's is low power usage (great in my laptop), no heat and you can mount them any almost anywhere with double stick tape or Velcro.

Sata II or Sata III would depend on your Motherboard. Sata II works fine, Sata III is current and will probably cost more. The Motherboard and Processor also affect the speed you get. If your the type of person who likes to sit around benchmarking your drive trying to achieve the best possible speed, let's just say you don't see any real life differences with your eyes.

I would shop for reliability over speed. The best warranty on a drive is the one you never have to use.
Escro and Poofyhairguy have guides pertaining to Solid State Drives. I'm sure if what they recommend had problems, we all would know about it by now, and they would have changed it.
Don't worry so much about speed, unless booting your system in 4 seconds is important to you and you don't mind spending the money for it. That's really the only difference you will see, after that it's pretty much all the same.

http://forum.xbmc.org/showthread.php?tid=94268


* Depending on the controller in your drive, it is suggested to leave your system logged off or at a boot screen once and a while to give the controller time to clean the drive. That will help restore/maintain the speed. I usually do this overnight about every 6 weeks or so.
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#3
@aptalca

It sounds like you think read speeds only apply when copying files from the SSD to another drive ?
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#4
>>X<<' Wrote:@aptalca

It sounds like you think read speeds only apply when copying files from the SSD to another drive ?

No of course not. I was talking about "maximum" read speeds when I referred to copying one file to another drive. Because that's usually the scenario you're most likely to reach (and be able to measure) the "maximum" read speed advertised, which is usually sequential.

Then I made the distinction between sequential read speeds and random access. Because "random access" read speeds cause the bottleneck when, say you're browsing through your movie library using a heavier skin such as Transparency and as you scroll quickly, xbmc (thus the drive) is trying to keep up with loading and displaying each thumbnail and fanart, trying to read a ton of small individual files one after another. (That process is called random access, right?)


Driver 944,

thanks for your reply as well. But I think you misunderstood me. I am not a spec junkie that tries to get the fastest component ever. I never cared to benchmark anything in my life and I really don't care about the boot speed as I usually leave the computer on or put it in sleep mode. Sata II and III don't matter either because the random access speeds will not likely reach the max Sata II speed anyway.

The only reason I brought this up is because that article I had read about a year ago (I can not seem to find it anymore) made it sound like some SSDs actually have pretty bad random access speeds that might be even slower than 7200rpm HDDs.

I am tempted to get an SSD to make my htpc running transparency more responsive. Currently I am using a 7200rpm HDD and transparency has some lag when browsing/scrolling. It's not too bad, but it would be nice without it. I know the cpu and the gpu are not the bottlenecks, and most likely the HDD is. If I get an SSD for the sole purpose of making xbmc more responsive and end up with an SSD with random access speeds comparable to my HDD, it will be a waste of money and time as I won't see much of a difference. And I am also going to get a relatively cheaper SSD because I am not the type that spends a ton of money on higher end components so I need to do my research.
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#5
i know what your saying aptalga but, the thing is,
to know stable read speed of a particular SSD drive
you'll have to digg in and search for reviews on it,,,

on my end, i still like SSD's, since i use windows7,
i boot in it in 34 seconds on my SATAII 32GB SSD..
its a corsair nova with 195MB/s read speeds...

i just love them, cant wait to try SATAIII SSD's..
yes, they are pricey, but whether they are worth it
for the price its up to your own judgement,,
but i say YES,,

But here's the thing,
i think that the SSD wont make your XBMC skin
more snappy,,,
SSD will help when loading 1080P fanart,
but about menu transitions, i doubt it,,,

hope this helps
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