AHCI vs. IDE Linux Performance Benchmarks

[phoronix]

Phoronix: AHCI vs. IDE Linux Performance Benchmarks

Hitting OpenBenchmarking.org this weekend are some interesting benchmarks comparing performance of AHCI vs. IDE modes under Linux from an AMD Fusion system...

http://www.phoronix.com/vr.php?view=MTE0OTE

[mo0n_sniper]

For an evolution of a standard it sure looks dissapointing from those benchmarks

[uid313]

It is too bad that libata maintainer Andre Hedrick recently committed suicide.

https://lwn.net/Articles/508222/

[DeepDayze]

It is too bad that libata maintainer Andre Hedrick recently committed suicide.

https://lwn.net/Articles/508222/

Ouch...who's stepping forward to take his place, as this is an important library?

[devius]

I suppose this is a typical 5400 rpm HDD so it's kind of expected that it doesn't make much difference. Try the same thing with a fast SSD and see if the results are the same.

[uid313]

Ouch...who's stepping forward to take his place, as this is an important library?

I don't know. Perhaps Jeff Garzik?

https://lwn.net/Articles/508467/

[MeduZa]

I suppose this is a typical 5400 rpm HDD so it's kind of expected that it doesn't make much difference. Try the same thing with a fast SSD and see if the results are the same.

I agree with that

[RealNC]

With disk drives, AHCI is not so much about performance, but about SATA (like hotswapping.) With fast disks, there's a bit of a performance advantage with non-sequential reads due to NQC, but it's not much (it's limited compared to SCSI.) However, it also helps the drive's read head live longer as it travels less.

Note that SSDs don't have heads, so NQC is useless here. Access to the higher bandwidth however, is useful for fast SSDs.

[Kano]

Your description is wrong, first it's NCQ and it is not limited to reads:

http://en.wikipedia.org/wiki/Native_Command_Queuing

[bug77]

I suppose this is a typical 5400 rpm HDD so it's kind of expected that it doesn't make much difference. Try the same thing with a fast SSD and see if the results are the same.

You've got it backwards. For slower drives, NCQ should help a lot, as heads won't have to seel as much. However, in my experience the difference is no noticeable.
For SSDs, NCQ means nothing.
Other AHCI improvements are not about speed (afaik).