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I just bought a new pc with ASUS P8P67-M PRO motherboard with OCZ Vertex 2 60GB and Caviar Black 1TB 64MB Cache, both on AHCI.

I tested them using CrystalDiskMark. The strange thing is that the HDD gives me rate of 450mb/s read, 120mb/s write, and the SSD gives me only 200mb/s read, 70mb/s write.

  • Is it possible for the HDD to have such big read values?
  • Are those normal values for the Vertex 2
  • If both are normal, what should I use for OS drive
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up vote 4 down vote accepted
  1. Yes, if you use really bad setting for CrystalDiskMark when benchmarking. You probably changed to the smallest test, which means that with a little read ahead you just end up reading from the cache. This is much faster on the Caviar Black than the Vertex 2 because the the Caviar Black has a 6 Gbps SATA port while the the Vertex 2 only has a 3Gbps SATA port. Change back to default setting and you will get better results. Use default setting for CrystalDiskMark instead.
  2. Pretty normal, yes. The write is so low because the Vertex 2 has run out of clean blocks and has to run garbage collection while writing. Avoid benchmarking it for a while and the speed should pick back up.
  3. Definitely the Vertex 2. It is much faster. You shouldn't be looking at the sequential numbers, you should be looking at the 4k numbers. They are much more representative of what using a desktop computer is like.
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Thank you for your answer. I'm using the default settings on the both drives here are the full benchmarks. Is this ok? – blez Mar 31 '11 at 22:32
Those are not the default settings. The default benchmark settings use a test size of 1000MB, not 50MB as in your benchmark numbers. The Caviar Black has 64MB of cache. With a 50MB test the whole test fits in the cache. – Mr Alpha Apr 1 '11 at 9:53
Aha, I get it now. Thanks. – blez Apr 1 '11 at 13:31

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