The SSD Relapse: Understanding and Choosing the Best SSD
by Anand Lal Shimpi on August 30, 2009 12:00 AM EST- Posted in
- Storage
Used vs. New Performance: Revisited
Nearly all good SSDs perform le sweet when brand new. None of the blocks have any data in them, each write is performed at full speed, all is bueno. Over time, your drive gets written to, all blocks get occupied with data (both valid and invalid) and now every time you write to the SSD its controller has to do that painful read modify write and cleaning.
In the Anthology I simulated this worst used case by first filling the drive with data, deleting the partition, then installing the OS and running my benchmarks. This worked very well because it filled every single flash block with data. The OS installation and actual testing added a few sprinkles of randomness that helped make the scenario even more strenuous, which I liked.
The problem here is that if a drive properly supports TRIM, the act of formatting the drive will erase all of the wonderful used data I purposefully filled the drive with. My “used” case on a drive supporting TRIM will now just be like testing a drive in a brand new state.
To prove this point I provide you with an example of what happens when you take a drive supporting TRIM, fill it with data and then format the drive:
SuperTalent UltraDrive GX 1711 | 4KB Random Write IOPS |
Clean Drive | 13.1 MB/s |
Used Drive | 6.93 MB/s |
Used Drive After TRIM | 12.9 MB/s |
Oh look, performance doesn’t really change. The cleaning process takes longer now but other than that, the performance is the same.
So, I need a new way to test. It’s a shame because I’m particularly attached to the old way I tested, mostly because it provides a very stressful situation for the drives to deal with. After all, I don’t want to fool anyone into thinking a drive is faster than it is.
Once TRIM is enabled on all drives, the way I will test is by filling a drive after it’s been graced with an OS. I will fill it with both valid and invalid data, delete the invalid data and measure performance. This will measure how well the drive performs closer to capacity as well as how well it can TRIM data.
Unfortunately, no drives properly support TRIM yet. The beta Indilinx firmware with TRIM support works well, unless you put your system to sleep. Then there’s a chance you might lose your data. Woops. There’s also the problem with Intel’s Matrix Storage Manager not passing TRIM to your drives. All of this will get fixed before the end of the year, but it’s just a bit too early to get TRIM happy.
What we get today is the first stage of migrating the way we test. In order to simulate a real user environment I take a freshly secure erased drive, install Windows 7 x64 on it (no cloning, full install this time), then install drivers/apps, then fill the remaining space on the drive and delete it. This fills the drive with invalid data that the drive must keep track of and juggle, much like what you'd see by simply using your system.
I’m using the latest IMSM driver so TRIM doesn’t get passed to the drives; I’m such a jerk to these poor SSDs.
I’ll start look at both new and used performance on the coming pages. Once TRIM gets here in full force I’ll just start using it and we won't have to worry about looking at new vs. used performance.
The Test
CPU | Intel Core i7 965 running at 3.2GHz (Turbo & EIST Disabled) |
Motherboard: | Intel DX58SO (Intel X58) |
Chipset: | Intel X58 |
Chipset Drivers: | Intel 9.1.1.1015 + Intel IMSM 8.9 |
Memory: | Qimonda DDR3-1066 4 x 1GB (7-7-7-20) |
Video Card: | eVGA GeForce GTX 285 |
Video Drivers: | NVIDIA ForceWare 190.38 64-bit |
Desktop Resolution: | 1920 x 1200 |
OS: | Windows 7 x64 |
295 Comments
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Bonesdad - Sunday, October 10, 2010 - link
Been over a year since this article was published...still very relevant. Any plans to update it with the latest products/drivers/firmware? There have been some significant updates, and it would be good to at least have updated comparisons.Well done, more more more!
hescominsoon - Thursday, February 17, 2011 - link
Excellent article but you left out sandforce. I'm curious if this was an oversight or a purposeful moission.PHT - Friday, September 28, 2012 - link
This article is fantastic, the best I ever read about SSD.Any follow up with new SATA III drives and new controllers like SandForce, new Indilinx etc.?
I will be glad to see it.
My Best
Zygmunt
lucasgonz - Wednesday, October 16, 2013 - link
Hello everyone.This post is quite old but I hope someone can answer.
I am concerned about the life of my ssd (sandisk extreme 240). I performed partitions ignoring the issue of the level of wear and partitions. I have it for one year ago with a 30gb partition and one with 200GB. I wanted to use large drive for data but I did not have time for that and just use the first 30gb partition . My question is if the ssd may be damaged by using only a little segment. DiskInfo shows 10tb reading 18 tb and writing.
sorry my poor English.
Thanks for any help.
Ojaswin Singh - Monday, January 13, 2014 - link
Hey,This is the most informative article i have ever read.Can You Please clear Out Some Of my Doubts:-1.Does Playing Video Games or Running Programs add to Writing on the SSD
2.Is 1 Write Cycle=Filling 120GB of SSD once
3.I really write on my HDD a lot(Seriusly a Lot) So how much life cycle can i expect from Samsung 840 SSD(Neither Pro nor EVO) I mean for how much time can i expect it to be writable
Please Help me cause i want the speeds of SSD but i want it to last for me too
Thanks,
Ojaswin