If there’s one thing we've learned from deconstructing the traces of a number of games and productivity apps, it’s that queue depth generally stays at one when you’re using an SSD. For that reason, we’re revamping our random read, random write, sequential read, and sequential write tests. If you're unfamiliar with those terms and what they represent, you can refer back to page three of SSD Performance In Crysis 2, World Of Warcraft, And Civilization V.
In the past, we've tested random transfers by benchmarking with four workers active in Iometer. This mimics threaded environment, as each worker represents a different application accessing the drive. However, that approach also ends up overstating the results because four workers with one outstanding I/O operation each translates into a queue depth of four. In order to make things more realistic, we cut the number of workers to one, actually yielding a queue depth of one.
At a queue depth of one, the 64 GB 830 continues to nip at the heels of Crucial's 128 GB m4, while the 64 GB m4 follows close behind. The slowest drives are the two 60 GB SF-22xx-based SSDs.
As we scale up queue depth, the 60 GB SandForce-based drives continue turning in relatively poor results. Even at a queue depth of 32, neither drive is able to break the 100 MB/s barrier.
Interestingly, Samsung’s 64 GB 830 performs just as fast as its larger-capacity relative at higher queue depths. That’s not the same story with the m4s, which jockey for position.
Here, we see the m4s scale fairly well with capacity once you move up to a queue depth of two or greater. With one outstanding I/O operation, there’s only a 16 MB/s delta between the best (60 GB SandForce-based drive with asynchronous memory) and worst (64 GB m4) performers.
At higher queue depths, both 60 GB SandForce-based offerings start to pull ahead of the pack, but performance starts to tank at a queue depth of 16. Meanwhile, Samsung’s 64 GB 830 performs consistently at ~75 MB/s across all queue depths. The 64 GB m4 is about 25 MB/s faster.
- Which 64 GB SSD Is The Best?
- Simplfying The SandForce Landscape
- Test Setup And Benchmarks
- Benchmark Results: Storage Bench v1.0 And PCMark 7
- Benchmark Results: 4 KB Random Performance
- Benchmark Results: 128 KB Sequential Performance
- SandForce: Incompressible Performance
- Real-World Tests
- Crowning An Entry-Level SSD Performance King
- Storage Bench v1.0, In More Detail
- More Background On Our Benchmarks