The Impact of Spare Area on SandForce, More Capacity At No Performance Loss?
by Anand Lal Shimpi on May 3, 2010 2:08 AM ESTAnandTech Storage Bench
Note that our 6Gbps controller driver isn't supported by our custom storage bench here, so the C300 results are only offered in 3Gbps mode.
The first in our benchmark suite is a light usage case. The Windows 7 system is loaded with Firefox, Office 2007 and Adobe Reader among other applications. With Firefox we browse web pages like Facebook, AnandTech, Digg and other sites. Outlook is also running and we use it to check emails, create and send a message with a PDF attachment. Adobe Reader is used to view some PDFs. Excel 2007 is used to create a spreadsheet, graphs and save the document. The same goes for Word 2007. We open and step through a presentation in PowerPoint 2007 received as an email attachment before saving it to the desktop. Finally we watch a bit of a Firefly episode in Windows Media Player 11.
There’s some level of multitasking going on here but it’s not unreasonable by any means. Generally the application tasks proceed linearly, with the exception of things like web browsing which may happen in between one of the other tasks.
The recording is played back on all of our drives here today. Remember that we’re isolating disk performance, all we’re doing is playing back every single disk access that happened in that ~5 minute period of usage. The light workload is composed of 37,501 reads and 20,268 writes. Over 30% of the IOs are 4KB, 11% are 16KB, 22% are 32KB and approximately 13% are 64KB in size. Less than 30% of the operations are absolutely sequential in nature. Average queue depth is 6.09 IOs.
The performance results are reported in average I/O Operations per Second (IOPS):
If there’s a light usage case there’s bound to be a heavy one. In this test we have Microsoft Security Essentials running in the background with real time virus scanning enabled. We also perform a quick scan in the middle of the test. Firefox, Outlook, Excel, Word and Powerpoint are all used the same as they were in the light test. We add Photoshop CS4 to the mix, opening a bunch of 12MP images, editing them, then saving them as highly compressed JPGs for web publishing. Windows 7’s picture viewer is used to view a bunch of pictures on the hard drive. We use 7-zip to create and extract .7z archives. Downloading is also prominently featured in our heavy test; we download large files from the Internet during portions of the benchmark, as well as use uTorrent to grab a couple of torrents. Some of the applications in use are installed during the benchmark, Windows updates are also installed. Towards the end of the test we launch World of Warcraft, play for a few minutes, then delete the folder. This test also takes into account all of the disk accesses that happen while the OS is booting.
The benchmark is 22 minutes long and it consists of 128,895 read operations and 72,411 write operations. Roughly 44% of all IOs were sequential. Approximately 30% of all accesses were 4KB in size, 12% were 16KB in size, 14% were 32KB and 20% were 64KB. Average queue depth was 3.59.
The gaming workload is made up of 75,206 read operations and only 4,592 write operations. Only 20% of the accesses are 4KB in size, nearly 40% are 64KB and 20% are 32KB. A whopping 69% of the IOs are sequential, meaning this is predominantly a sequential read benchmark. The average queue depth is 7.76 IOs.
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StormyParis - Monday, May 3, 2010 - link
it seems SSD perf is the new dick size ?Belard - Tuesday, May 4, 2010 - link
No, it has nothing to do with "mine is bigger than yours"...They are still somewhat expensive. But when you use one in a notebook or desktop, it makes your computer SO much more faster. Its about SPEED>
Applications like Word or Photoshop are ready to go by the time your finger leaves the mouse button. Windows7 - fully configured (not just some clean / bare install) boots in about 10 seconds (7~14sec depending on the CPU/Mobo & software used)... compared to a 7200RPM drive in 20~55seconds.
And that is with todays X25-G2 drives using SATA 2.0. Imagine in about 2 years, a $100 should get you 128GB that can READ upwards of 450+ MB/s.
Back in the OLD days, my old Amiga 1000 would boot the OS off a floppy in about 45 seconds, with the HD installed, closer to 10 seconds.
I'll admit that Win7's sleep mode works very good with a wake up time on a HDD that is about 3~5 seconds.
neoflux - Friday, June 11, 2010 - link
Wow, someone's an internet douche.Maybe you need to look at the overall system benchmarks, like PCMark Vantage or the AnandTech Storage Bench, where your precious Intels are destroyed by the SF-based drives.
And even if you look at the random reads/writes, the Intels are again destroyed on the writes and the same speed for the reads. I'm of course looking at the aligned benchmarks (aligned read not in this article, but shown here: http://www.anandtech.com/bench/SSD/83 ), because I'm actually being objective and realistic about how SSDs are used rather than trying to justify my purchases/recommendations.
buggyfunbunny - Monday, May 3, 2010 - link
What I'd like to see added to the TestBench, for all drive types (not just SSD), is a Real World, highly (or fully) normalized relational database. Selects, inserts, updates, deletes. The main reason for SSDs will turn out to be such join intensive databases; massive file systems, awash in redundant data, will always out pace silicon storage. In Real World size, tens of gigabytes running transactions. The TPC suite would be nice, but AT may not want to spend the money to join. Any consistent test is fine, but should implement joins over flat-file structures.Zan Lynx - Monday, May 3, 2010 - link
Big databases don't bother with SATA SSDs. They go straight to PCI-e direct-connected SSD, like Fusion-IO and others.If you want fast, you have to get rid of the overhead associated with SATA. SATA protocol overhead is really a big waste of time.
FunBunny - Monday, May 3, 2010 - link
Of course they do. PCIe "drives" aren't drives, and are limited to the number of slots. This approach works OK if you're taking the Google way: one server one drive. That's not the point. One wants a centralized, controlled datastore. That's what BCNF databases are all about. (Massive flatfiles aren't databases, even if they're stored in a crippled engine like MySql.) Such databases talk to some sort of storage array; an SSD one running BCNF data will be faster than some kiddie koders java talking to files (kiddie koders don't know that what they're building is just like their grandfathers' COBOL messes; but that's another episode).In any case, the point is to subject all drives to join intensive datastores, to see which ones do best. PCIe will likely be faster in pure I/O (but not necessarily in retrieving the joined data) than SSD or HDD, but that's OK; some databases can work that way, most won't. Last I checked, the Fusion (which, if you've looked, now expressly say their parts AREN'T SSD) parts are substantially more expensive than the "consumer" parts that AT has been looking at. That said, storage vendors have been using commodity HDD (suitably QA'd) for years. In due time, the same will be true for SSD array vending.
Zan Lynx - Monday, May 3, 2010 - link
It is solid state. It stores data and looks like a drive to the OS. That makes it a SSD by my definition.I wonder why Fusion-IO wants to claim their devices aren't SSDs? My guess is that they just don't want people thinking their devices are the same as SATA SSDs.
jimhsu - Monday, May 3, 2010 - link
Hey Anand,I'm not doubting your Intel performance figures, but I wonder why your benchmarks only show about a 20% performance decrease, when threads like this (http://forums.anandtech.com/showthread.php?t=20699... show that it is possibly quite more? (20% is just on the edge of human perception, and I can tell you that a completely full X25-M does really feel much slower than that). Is the decrease in performance different for read vs/ write, sequential vs. random? Are you using the drive in an OS context (where the drive is constantly being hit with small read/writes while the benchmark is running)?
Anand Lal Shimpi - Monday, May 3, 2010 - link
20% is a pretty decent sized hit. Also note that it's not really a matter of how full your drive is, but how you fill the drive. If you look back at the SSD Relapse article I did you'll see that SSDs like to be written to in a nice sequential manner. A lot of small random writes all over the drive and you run into performance problems much faster. This is one reason I've been very interested in looking at how resilient the SF drives are, they seem to be much better than Intel at this point.Take care,
Anand
FunBunnyBuggyBuggy - Tuesday, May 4, 2010 - link
(first: two issues; the login refuses to retain so I've had to create a new each time I comment which is a pain, and I wanted to re-read the Relapse to refresh my memory but it gets flagged as an Attack Site on FF 3.0.X)-- If you look back at the SSD Relapse article I did you'll see that SSDs like to be written to in a nice sequential manner.
I'm still not convinced that this is strictly true. Controllers are wont to maximize performance and wear-leveling. The assumption is that what is a sequential operation from the point of view of application/OS is so on the "disc"; which is strictly true for a HDD, and measurements bear this out. For SSD, the reality is murkier. As you've pointed out, spare area is not a sequestered group of NAND cells, but NAND cells with a Flag; thus spare move around, presumably in erase block size. A sequential write may not only appear in non-contiguous blocks, but also in non-pure blocks, that is, blocks with data unrelated to the sequential write request from the application/OS. Whichever approach maximizes the controller writers notion of the trade off between performance requirement and wear level requirement will determine the physical write.