One of the reasons we brought back fresh out-of-box testing in Iometer was to free up time to explore other aspects of performance. For this round-up, we specifically want to investigate the read performance of a full drive. After all, a 60 GB drive isn't very large, so it's very likely that you'll be dealing with this exact scenario on and off.
In theory, read speeds shouldn't be significantly impacted by the drive's free space. But there is a noticeable drop-off on the lower-capacity SF-22xx-based SSDs. Compression is one reason for this. Compressed data has to be decompressed, which requires sufficient free space. SandForce's garbage collection mechanism is a second explanation. Because most of its clean-up happens in the foreground, decompression requires a rotation of scratch space so that the NAND wears out evenly. This is known as wear leveling.
Both factors penalize the 60 GB drives we're rounding up more than the larger models as a result of limited NAND bandwidth, a side-effect of leaning on fewer NAND dies. We're using HD Tune to illustrate.

The image above shows how read performance varies. After using Acronis True Image Home to clone our system drive, we set HD Tune to read the entire LBA space sequentially. As you can see, reading back information written to our 60 GB Agility 3 falls between 150-200 MB/s. Once we move on to free space, performance accelerates to 450 MB/s. That's a big difference.

But what happens when we get more specific and narrow our focus to incompressible data? After adding about 6 GB of MP3s and H.264-encoded video, we can clearly discern performance at its worst on a SandForce-based drive. Read performance drops to about 150 MB/s. That's why you see performance bounce up and down when we only have Windows and a few apps installed: some of that data is compressible, and some isn't.
That's not the end of the story, though. We repeated this same tests on all of the drives in our round-up and found that the results only apply to 60 GB SF-22xx-based SSDs accessing asynchronous NAND. Let's take Intel's SSD 520 for a spin to compare the performance of a drive with higher-performing synchronous flash.

We already established (using early Iometer testing) that reading back free space is similar regardless of a drive's NAND interface. Yet, comparing the SSD 520 to OCZ's Agility 3, we see read performance in the space occupied by Windows and our application data falls between 250-300 MB/s. In a worst-case scenario, incompressible data is read back at 250 MB/s. Sure, that's low compared to the 450 MB/s we see otherwise. But it's also 100 MB/s faster than the 60 GB Agility 3 and its asynchronous NAND-based competition.
Now, to put it all in context. Check out the results from our 64 GB m4 in the chart below. Crucial mostly employs background garbage collection, and it doesn't lean on compression for its commendable performance. As a result, read performance is largely unaffected by fill state.

- The Great 60 GB SandForce SSD Round-Up
- Test Setup And Firmware Notes
- 4 KB Random Performance
- 128 KB Sequential Performance
- Incompressible Sequential Write Performance: SandForce's Weakness
- PCMark 7 And Power Consumption
- Endurance Testing
- Exploring The Performance Of A Full SandForce-Based SSD
- Performance Is Defined By Flash
Ms-Office
Adobe pdf reader
a web browser, a photo manipulating program
a music/video player.
Install a game from a ISO.
An antivirus
And all these apps should be installed from the SSD itself (meaning their setups should be on the SSD).
Then you should test the startup and shutdown times.
All these synthetic benchies dont make much sense, IMHO.
Ms-Office
Adobe pdf reader
a web browser, a photo manipulating program
a music/video player.
Install a game from a ISO.
An antivirus
And all these apps should be installed from the SSD itself (meaning their setups should be on the SSD).
Then you should test the startup and shutdown times.
All these synthetic benchies dont make much sense, IMHO.
A lot of operations use only a single core and the SSD cant use its true potential. That is, the CPU cant process data as fast as the SSD can provide.
This is just reverse of what happens in case of mechanical HDD's.
You're not going to see a major difference.
Well, it is pointless though since everything you are doing is so fast that it doesn't matter anymore. I however see your point since I can be loading a program and my SSD is not even at max speed my CPU frequency is maxed out. The only way to get more speed is to just overclock as much as you can.
that is the point of buying a cheaper SSD based on a chepaer NAND.
I'd also like to see small drives benchmarked as swap drives in video editing machines. Currently I'm using a raid 0 array of 1tb samsung drives that keeps up well enough, but I'd be interested to see if there are tangible productivity differences.
For a future SSD review/roundup could you take, for example, 10 real-life traces from 10 different editor's machines (the more variation in workload, the better), and then compare the %change in execution time vs. a reference drive?
Great article.
Can we get a "Best motherboards for the money" type?
Thanks.
You can comment on, wish for, or suggest a product be tested without implying there's some kind of intentional skewing or fault in the data collected.
I recommend upping your budget to a larger drive. Otherwise m4.
I already do that, just pick up a cheap 30-64GB SSD and move the virtually memory over to it. As for killing the page file well good luck as that doesn't work. If it did there would be 36gb worth of more free space. As for using a ssd for only page file well it really does work and it doesn't degrade as quickly as you might think. When there is no static data for the controller to deal with while there is high read/write the drive tends to not have the same issues as most get. Just under 6,000 hours of heavy use and my 30gb kingston ssd is holding up.
It's a bloody long test that I've decided to reserve for comparing between different SSDs employing different controllers. It would have probably taken a full week to test all the SSDs and that only would happen if we were test 24x7 and perfectly timed the drive swaps ;p
We sent an invitation to Mushkin. They did not respond in proper time for this roundup. In any event, Toggle at 60 GB is quite rare. Though, I agree, it would have been an interesting contender. Unfortunately, we didn't want to put the roundup on the back burner any longer, because we've made multiple postponements to accommodate this that and the other.
Cheers,
Andrew Ku
TomsHardware.com
I believe you're referring to our Best SSDs column? If you want something different, feel free to suggest it.
Sure! Read our controller agnostic 60 GB roundup.
Cheers,
Andrew Ku
TomsHardware.com