Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 22 Oct 2003 13:27:59 +0200 | From | Knut Petersen <> | Subject | Re: VIA IDE performance under 2.6.0-test7/8? |
| |
Hi James!
> Can you also send the output from "cat /proc/interrupts". > It looks like you are not using IO-APIC, but instead using XT-PIC. > XT-PIC is a lot slower than IO-APIC.
Reading the previous messages I compared the SuSE 2.4.20-4GB and the 2.6.0-test8-bk1 kernel.
The mainboard is a VIA EPIA 5000 (cpu Via Eden 533 Mhz, Via 8601A Northbridge, VT8231 Southbridge)
hdparm -I /dev/hd? displays no difference ... udma2 is the used mode.
hdparm -T /dev/hd? measures transfer rates of 60-63 MB/s, there is no significant difference between the kernel versions.
hdparm -t /dev/hd? mesasures 18 MB/s for kernel 2.6.0-test8-bk1 and 27 MB/s for kernel 2.4.20. This is a significant :-(
2.4.20 gives almost exactly 50% better performance compared to 2.6.0-test8 ... is this pure accident or could this give a hint?
> Just turn on SMB support in the "make menuconf", and it should enable > IO-APIC.
Compiling the kernel with and without smb support as well as trying the other APIC related new configuration options does change nothing. There is allways a "No local APIC present or hardware disabled" message. I believe that there really is no IO-APIC, at least I found no related BIOS configuration option.
/proc/interrupts indicates an XT-PIC for both kernel versions.
IRQ setup is identical, IDE IRQs are not shared with any other devices.
The drive is the only drive attached.
Playing around with different read-ahead values does not help.
Any ideas?
cu, Knut Petersen
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| ![\](/images/icornerr.gif) |