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 |
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IPL - Monday, August 31, 2009 - link
I first started reading anandtech when I got seriously interested in SSDs and honestly, you write the best SSD articles around! Thank you for all the help you gave me in deciding which SSD to buy.I ordered online the new G2 last week and should be getting it in a few days. I live in Greece and the re-launched G2 has been available here for about a week now.
I am planning on replacing the HDD on my Feb 08 Macbook Pro (last refresh pre-unibody) as soon as I get it. I am just a consumer with a little bit of knowledge on tech but not a pro at all. I just thought of asking all a few questions that I have pre-drive swapping.
1. Will TRIM be supported on macs? Any news if and when?
2. When then new TRIM firmware is out, do I have to just install the firmware or will I need to format everything and start from fresh in order to get it to work?
3. I have bought a 2,5'' SATA USB enclosure in order to put my G2 in there first, connect it to the laptop via the USB and install Snow Leopard from there. After I am done, I will remove the G2 from the enclosure, swap the drives and hopefully, everything will be working. Does this sound logical? I am worried about the h/w drivers to be honest.
Thanks in advance for your help. I will post some non-scientific time results as soon as get this done. Cant wait.
gstrickler - Monday, August 31, 2009 - link
The simplest way to swap the HD on most Mac OS machines is:1. Connect both the old and the new drive to the machine (internally or in an external USB or FireWire case).
2. Use Disk Utility (included in Mac OS X) to set the appropriate partitioning scheme (GUID for Intel based Macs, Apple Partition Scheme for PPC Macs) on the new drive.
3. Partition and format the new drive.
4. Use Carbon Copy Cloner (shareware) to clone the old drive to the new drive.
5. Try booting off the new drive. Note that PPC Macs can't boot from USB drives, but Intel based Macs can. All PPC and Intel Macs with a built-in FireWire port can boot from a FireWire drive.
6. If not already done, physically swap the drives to the desired locations, boot and set the preferred startup drive.
IPL - Tuesday, September 1, 2009 - link
Awesome, thanks for the help.I have checked Carbon Copy Cloner and it is already one of my options. Never tried it before but looked easy enough.
I havent decided yet which way I will do it (fresh install or clone existing drive) but I will make my mind up when everything is ready!
Anand Lal Shimpi - Monday, August 31, 2009 - link
Thank you for reading and saying such wonderful things, I really do appreciate it :)1) I don't believe TRIM is presently supported in Snow Leopard. I've heard that Apple may be working on it but I don't think it's there now.
2) From what I've seen, it should preserve your data. It's still worth backing up just in case something ridiculous happens.
3) What you're describing should work, although if I were you I'd just swap the drives and install. Hook your old drive up via USB and pull any data you need off of that.
Take care,
Anand
sunbear - Monday, August 31, 2009 - link
Another fantastic article. I just wanted to draw your attention to recent reports that the majority of currently available laptops (including the MacBookPro) are unable to support transfer rates greater than SATA-150 (http://www.hardmac.com/news/2009/06/16/new-macbook...">http://www.hardmac.com/news/2009/06/16/...imited-1....Since most laptops can't even use the full performance of these SSD's, do you have any recommendation regarding which one would be the best bang-for-the-buck to speed up a laptop?
Personally, I am interested in putting SSD's in a laptop not only for the speed improvements, but I'm also hoping that it reduces the amount of heat that my laptop will put out so that I can finally find a laptop that you can use comfortably on your lap!
Incidentally, it would be really great if laptop reviewers checked to see if they could comfortably work with a laptop at full load on their lap as a standard test.
Anand Lal Shimpi - Monday, August 31, 2009 - link
Even on a SATA-150 interface, you're generally only going to be limiting your sequential read speed and perhaps your sequential write speed a bit. Random read/write speeds don't really go above 60MB/s so you're fine there.They recommendations remain the same; Intel at the top end, anything Indilinx MLC to save a bit. If anything, a SATA-150 interface makes the Intel drive look a bit better since its 80MB/s sequential write limit isn't as embarrassing :)
Take care,
Anand
Dobs - Monday, August 31, 2009 - link
I hope Seagate / Western Digital etc. bring even more innovation / competition in SSD's next year... and not just Enterprise products.And one thing I don't fully understand is why there aren't more dedicated 3.5" drives. Patriot has the adapter but what about the rest??? No money in desktops anymore???
Anand Lal Shimpi - Monday, August 31, 2009 - link
OCZ is making a 3.5" Vertex drive, waiting on it for review :)Take care,
Anand
kisjoink - Monday, August 31, 2009 - link
Now that the good performing SSDs are half the price of last year, I'd really like to see a 2xSSD in RAID 0 article!mgrmgr - Monday, August 31, 2009 - link
I second the request for a 2xSSD RAID-0 article...with specific discussions about which applications it benefits (Photoshop?) and which ones it doesn't.Before October 22nd when I buy a new Win7 computer? Please. :-)