Messages in this thread | | | Date | Fri, 24 Nov 2006 14:30:27 +0000 | From | "Daniel J Blueman" <> | Subject | Re: SATA Performance with Intel ICH6 |
| |
I'm having the same issue - I have an ICH6M w/ SATAII-300 disk (running in SATA I-150 mode), running in native AHCI mode. Processor is Pentium-M 1.7GHz 2MB L2$, DDR2-667.
The kernel is stock-compiled 2.6.19-rc6 on current Debian stable (gcc 4.1.2) - and I saw this on previous kernels also. When read()ing 16KB or 1MB chunks from the disk, I'm getting 65MB/s (expected) [1], but at a surprising ~12% system time [2].
Oprofile [3] shows nothing unexpected. Kernel messages [4] look like it's configured correctly too. Spinlocks or what?
--- [1]
# dd if=/dev/sda of=/dev/null bs=1024k <Ctrl-C> 3532+0 records in 3531+0 records out 3702521856 bytes (3.7 GB) copied, 56.5266 seconds, 65.5 MB/s
--- [2]
# vmstat 2 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa [snip] 0 1 0 9532 537632 79812 0 0 0 0 1348 1217 0 11 0 89 0 1 0 9944 576888 41724 0 0 0 0 1343 1195 0 12 0 89
--- [3]
# opreport -lt1 CPU: PIII, speed 1700 MHz (estimated) Counted CPU_CLK_UNHALTED events (clocks processor is not halted) with a unit mask of 0x00 (No unit mask) count 100000 warning: /usr/lib/locale/locale-archive is not in a usable binary format. samples % app name symbol name 19710 38.9965 vmlinux __copy_to_user_ll 13573 26.8544 vmlinux default_idle 982 1.9429 vmlinux isolate_lru_pages 661 1.3078 vmlinux kmem_cache_free 521 1.0308 vmlinux kmem_cache_alloc
--- [4]
$ dmesg | less Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2 ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx ICH6: IDE controller at PCI slot 0000:00:1f.1 ACPI: PCI Interrupt 0000:00:1f.1[A] -> GSI 18 (level, low) -> IRQ 18 ICH6: chipset revision 4 ICH6: not 100% native mode: will probe irqs later ide0: BM-DMA at 0xf800-0xf807, BIOS settings: hda:DMA, hdb:pio Probing IDE interface ide0... hda: TRANSCEND, CFA DISK drive ide0 at 0x1f0-0x1f7,0x3f6 on irq 14 Probing IDE interface ide1... hda: max request size: 128KiB hda: 8124480 sectors (4159 MB) w/1KiB Cache, CHS=8060/16/63, DMA hda: hda1 hda2 ahci 0000:00:1f.2: version 2.0 ACPI: PCI Interrupt 0000:00:1f.2[B] -> GSI 19 (level, low) -> IRQ 19 PCI: Setting latency timer of device 0000:00:1f.2 to 64 ahci 0000:00:1f.2: AHCI 0001.0000 32 slots 4 ports 1.5 Gbps 0x5 impl IDE mode ahci 0000:00:1f.2: flags: 64bit ncq pm led slum part ata1: SATA max UDMA/133 cmd 0xF080E100 ctl 0x0 bmdma 0x0 irq 19 ata2: SATA max UDMA/133 cmd 0xF080E180 ctl 0x0 bmdma 0x0 irq 19 ata3: SATA max UDMA/133 cmd 0xF080E200 ctl 0x0 bmdma 0x0 irq 19 ata4: SATA max UDMA/133 cmd 0xF080E280 ctl 0x0 bmdma 0x0 irq 19 scsi0 : ahci ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300) ata1.00: ATA-7, max UDMA/133, 488397168 sectors: LBA48 NCQ (depth 31/32) ata1.00: ata1: dev 0 multi count 16 ata1.00: configured for UDMA/133 scsi1 : ahci ata2: SATA link down (SStatus 0 SControl 0) scsi2 : ahci ata3: SATA link down (SStatus 0 SControl 300) scsi3 : ahci ata4: SATA link down (SStatus 0 SControl 0) scsi 0:0:0:0: Direct-Access ATA HDT722525DLA380 V44O PQ: 0 ANSI: 5 SCSI device sda: 488397168 512-byte hdwr sectors (250059 MB) sda: Write Protect is off sda: Mode Sense: 00 3a 00 00 SCSI device sda: drive cache: write back SCSI device sda: 488397168 512-byte hdwr sectors (250059 MB) sda: Write Protect is off sda: Mode Sense: 00 3a 00 00 SCSI device sda: drive cache: write back sda: sda1 sda2 sd 0:0:0:0: Attached scsi disk sda
Alan wrote: > On Fri, 24 Nov 2006 14:07:01 +0100 > "Martin A. Fink" <fink@mpe.mpg.de> wrote: > > > If I understand the design of this chipset correctly, then I would have > > expected, that the CPU needs to do only few work, instead I found out, that > > writing to disk seems to be really hard work for the CPU. > > It has some work to do - the amount in question depends upon the file > system and device drivers in use. For very high throughput read up on > the O_DIRECT feature. > > > My final aim is to get around 140MB/s of data from 3 different Gigabit > > Ethernet cards and store it on 3 harddisk drives that perform 50MB/s. > > >From the SATA bus side there should be no problem. Each of the 4 SATAs on > > this ICH6 chipset are capable of 150MB/s. > > I doubt an ICH6 has the total memory bandwidth to achieve that to be > honest, but with PCI-E maybe you can. > > > So what makes my CPU that slow? Is it a hardware problem or a problem of > > SATA driver of my operating system? > > You don't give anything like enough information to even guess this. What > controller, what disks, what driver, what kernel version ? > > > By the way: I'm working with SuSE Linux 9.2 on a Dell Desktop PC, 1GB RAM > > For vendor kernels, especially older ones it is probably best to ask the > vendor first. > > Alan -- Daniel J Blueman - 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/
| |