The SSD Relapse: Understanding and Choosing the Best SSD
by Anand Lal Shimpi on August 30, 2009 12:00 AM EST- Posted in
- Storage
Random Read/Write Speed
This test writes 4KB in a completely random pattern over an 8GB space of the drive to simulate the sort of random writes that you'd see on an OS drive (even this is more stressful than a normal desktop user would see). I perform three concurrent IOs and run the test for 3 minutes. The results reported are in average MB/s over the entire time:
As we established in previous articles, the disk operations that feel the slowest are the random small file reads and writes. Both of which are easily handled by an SSD. A good friend of mine and former AnandTech Editor, Matthew Witheiler, asked me if he'd notice the performance improvement. I showed him the chart above.
He asked again if he'd notice. I said, emphatically, yes.
Now this is super interesting. Intel's X25-M G1 drops from 40.8MB/s when new down to 26.3MB/s in a well used state. Unfortunately for the G1, it will never get TRIM and will spend more time in the lower performance state over the life of the drive. But look at what happens with the X25-M G2: it drops from 36.1MB/s to 35.8MB/s - virtually no performance is lost. In fact, the G2 is so fast here that it outperforms the super expensive X25-E. Granted you don't get the lifespan of the X25-E and the SLC drive should perform better on more strenuous random write tests, but this is a major improvement.
The explanation? It actually boils down to the amount of memory on the drive. The X25-M G1 had 16MB of 166MHz SDRAM on-board, the G2 upped it to 32MB of slower 133MHz DRAM. Remember that Intel doesn't keep any user data in DRAM, it's only used for the remapping, defragmenting and tracking of all of the data being written to the drive. More DRAM means that the drive can now track more data, which means that even in the heaviest of random-write workloads you could toss at it on a normal desktop you will not actually lose any performance with the drive in a used state. And this is the drive Intel has decided to grant TRIM to.
The G2 is good.
The Indilinx drives do lose performance here. They drop from roughly 13MB/s down to 7MB/s. We're still talking ~5x the speed of a VelociRaptor, so there's no cause for alarm. But it's clear that even Indilinx's SLC drive can't match Intel's random write performance. And from what I hear, Intel's performance is only going to get better.
This is what the X25-M price premium gets you.
Bahahaha, look at the hard drive scores here: 0.7MB/s and 0.3MB/s? That's freakin' terrible! And that's why your system feels so slow when you start it up, there are a ton of concurrent random reads and writes happening all over the place which your hard drive crunches through at roughly 0.5MB/s. Even the Samsung based OCZ Summit manages a significant performance advantage here.
The Indilinx drives all cluster around the 30 - 40MB/s mark for random read performance, nothing to be ashamed of. The Intel drives kick it up a notch and give you roughly 60MB/s of random read performance. It's a noticeable improvement. As our application launch tests will show however, loading a single app on either an Indilinx or Intel drive will take about the same amount of time. It's only in the heavy multitasking and "seat of the pants" feel that you'll have a chance at feeling a difference.
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Mr Perfect - Tuesday, September 1, 2009 - link
Probably demand. When I saw that price, I shopped around to see what was going on. Answer? Everyone else seems to be out of stock.Naccah - Tuesday, September 1, 2009 - link
I've been waiting to get an SSD till Win 7 released hoping that the prices would have stabilized somewhat by that time. The recent price fluctuation is disturbing as well as the availability of the X25 G2. When the G2 first hit Newegg I was surfing the site and could have grabbed one for $230, but like I said I was content to wait. Now I'm having second thoughts! and wondering if I should grab one if the price goes down again.gfody - Tuesday, September 1, 2009 - link
That doesn't explain the 160gb - it's not even in stock yet. I have been waiting a month for this drive to be in stock and here they more than double the price one day before the ETA date! It's an outrage.. if I'd known the drive was $1000 I would have bought something else.Way to screw your customers Newegg
araczynski - Tuesday, September 1, 2009 - link
A) your intro has the familiar smell of tomshardware, you'd do to be without that, its unbecoming.B) your final words smell of the typical big corp establishment mentality; bigger, faster, more expensive, consumers want! while if the market is any indication, is completely the opposite of the truth. people want 'good enough' for cheap, as the recent Wired magazine article more or less said. granted, Wired isn't the source for indepth technical reading, but it is a good source sometimes of getting the pulse of things...sometimes, still, more often than anything coming out of the mouths of the big corps.
C) everything in between A and B is great though :) Please leave the opinions/spins to the PR machines.
Personally, the cost of these things is still more than i'm willing to pay for, for any speed increase. the idiotic shenanigans of firmwares and features only present after special downloads/phases of the moon make me just blow off the whole technology for a few more years. I'll revisit this in say 2 or 3 years, perhaps the MLC's will finally die off and the SLC's (unless i have the 2 backwards) or something better rolls out with a longer lifespan.
Anand Lal Shimpi - Tuesday, September 1, 2009 - link
A) My intention with the intro was to convey how difficult it was for me to even get to the point where I felt remotely comfortable publishing this article. I don't like posting something that I don't feel is worthy of the readership's reception. My sincere apologies if it came off as arrogant or anything other than an honest expression of how difficult it was to complete. I was simply trying to bring you all behind the scenes and take you into the crazy place that's my mind for a bit :)B) I agree that good enough for cheap is important, hence my Indilinx recommendation at the end. But we can't stifle innovation. We need bigger, better, faster (but not necessarily more expensive, thank you Moore's Law) to keep improving. I remember when the P3 hit 1GHz and everyone said we don't need faster CPUs. If we stopped back then we wouldn't have the apps/web we have today since developers can count on a large install base of very fast processors.
Imagine what happens in another decade when everyone has many-core CPUs in their notebooks...
Take care,
Anand
DynacomDave - Tuesday, September 29, 2009 - link
First - Anand thanks for the good work and the great article.I too have an older laptop that has a PATA interface that I'd like to upgrade with an SSD. I contacted Super Talent about their MasterDrive EX2 - IDE/PATA. Their response was; We only use Indilinx controller for SATA drives, like UltraDrive series. We use Phison controller for EX2/IDE drives.
I want to improve performance not degrade it. I don't know if this will perform like the Indilinx or like the old SSDs. Can anyone help me with this?
bji - Tuesday, September 1, 2009 - link
There are a few more smaller players in the SSD controller game that don't ever show up in these reviews. They are Silicon Motion and Mtron. The reason I am interested in them is because I have a laptop that is PATA only (it's old I know but I love it and I want to extend its life with an SSD), and I am trying to get an SSD that works in it.Turns out the Mtron MOBI SSDs are not compatible with this laptop. I have no idea why. So I have put an order into eBay for an SSDFactory SSD and am crossing my fingers that it will work.
Mtron makes SATA SSD drives so they could be included in these reviews, and I don't know why they are excluded. It would be interesting to see how their controllers stack up. I personally own two Mtron SSD drives (both 32 GB SLC drives) that I tried to get to work in my laptop and failed to - so one is now the system disk in my desktop and it is very fast (at least compared to platter drives, maybe not compared to newer SSDs). The other one I am still trying to find a use for.
The only Silicon Motion controller drives I have seen are PATA drives so they clearly are a different beast than the SATA drives typically reviewed in these articles. But I would still be interested in seeing the numbers for the Silicon Motion controller just to get an idea of how well they stack up against the other controllers, especially for the 4K random writes tests. The PATA interface ought not to be the limiting factor for that test at least.
paesan - Tuesday, September 1, 2009 - link
I see NewEgg has a Patriot Troqx and a Patriot Torqx M28. What is the difference in the 2 drives.paesan - Tuesday, September 1, 2009 - link
After reading thru the Patriot forum I found the differences. The M28 has 128MB cache compared to 64MB cache on the non M28. The biggest difference is the M28 uses a Samsung controller instead of the Indilinx controller on the non M28. I wonder why they switched controllers.valnar - Tuesday, September 1, 2009 - link
It seems to be that using trim would make a "used" SSD faster, no doubt, but is it required? Would it be okay to buy an SSD for a Windows XP box and just set and forget it? Even used and fragmented, it appears to be faster than any hard drive. My second question is longevity. How long would one last compared to a hard drive?