ata vs wd driver performance
I have recently performed some testing on the ata and wd drivers on my system. When writing to and reading from a file on the same file system in the same directory, the ata driver appears to take almost double the CPU time as compared to the wd driver. However, when reading from the raw disk, the ata and wd driver take about the same amount of CPU time. DMA is enabled in both driver. Can someone explain why the ata driver is using more CPU? Rich Straka [EMAIL PROTECTED] * wd driver results writing to a file. $ time dd if=/dev/zero of=test.dat bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 41.810011 secs (6420363 bytes/sec) real0m42.136s user0m0.002s sys 0m19.939s * ata driver results writing to a file. $ time dd if=/dev/zero of=test.dat bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 39.475358 secs (6800077 bytes/sec) real0m39.750s user0m0.008s sys 0m35.665s wd driver results reading from a file. $ time dd if=test.dat of=/dev/null bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 39.992958 secs (6712068 bytes/sec) real0m40.040s user0m0.025s sys 0m13.387s ata driver results reading from a file. $ time dd if=test.dat of=/dev/null bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 37.914618 secs (707 bytes/sec) real0m37.944s user0m0.009s sys 0m28.221s wd results reading from raw disk. $ time dd if=/dev/rwd0 of=/dev/null bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 33.100446 secs (8109723 bytes/sec) real0m33.137s user0m0.000s sys 0m0.266s ata results reading from raw disk. $ time dd if=/dev/rwd0 of=/dev/null bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 34.518500 secs (7776568 bytes/sec) real0m34.535s user0m0.000s sys 0m0.222s *** dmesg with wd driver. *** Copyright (c) 1992-1999 The FreeBSD Project. Copyright (c) 1982, 1986, 1989, 1991, 1993 The Regents of the University of California. All rights reserved. FreeBSD 4.0-CURRENT #1: Sat Dec 4 09:22:58 MST 1999 Timecounter "i8254" frequency 1193182 Hz Timecounter "TSC" frequency 333189478 Hz CPU: AMD-K6(tm) 3D processor (333.19-MHz 586-class CPU) Origin = "AuthenticAMD" Id = 0x580 Stepping = 0 Features=0x8001bfFPU,VME,DE,PSE,TSC,MSR,MCE,CX8,MMX AMD Features=0x8800SYSCALL,3DNow! real memory = 134152192 (131008K bytes) avail memory = 127021056 (124044K bytes) Preloaded elf kernel "kernel" at 0xc0303000. npx0: math processor on motherboard npx0: INT 16 interface pcib0: Host to PCI bridge on motherboard pci0: PCI bus on pcib0 pcib1: VIA 82C598MVP (Apollo MVP3) PCI-PCI (AGP) bridge at device 1.0 on pci0 pci1: PCI bus on pcib1 isab0: VIA 82C586 PCI-ISA bridge at device 7.0 on pci0 isa0: ISA bus on isab0 ide_pci0: VIA 82C586x (Apollo) Bus-master IDE controller at device 7.1 on pci0 chip1: VIA 82C586B ACPI interface at device 7.3 on pci0 sym0: 875 irq 10 at device 8.0 on pci0 sym0: Symbios NVRAM, ID 7, Fast-20, parity checking sym0: open drain IRQ line driver, using on-chip SRAM vga-pci0: Matrox MGA 2164W graphics accelerator at device 9.0 on pci0 fxp0: Intel EtherExpress Pro 10/100B Ethernet irq 12 at device 10.0 on pci0 fxp0: Ethernet address 00:a0:c9:27:fc:1d fdc0: NEC 72065B or clone at port 0x3f0-0x3f7 irq 6 drq 2 on isa0 fdc0: FIFO enabled, 8 bytes threshold fd0: 1440-KB 3.5" drive on fdc0 drive 0 wdc0 at port 0x1f0-0x1f7 irq 14 flags 0xa008a008 on isa0 wdc0: unit 0 (wd0): IBM-DCAA-34330, DMA, 32-bit, multi-block-8 wd0: 4134MB (8467200 sectors), 8400 cyls, 16 heads, 63 S/T, 512 B/S wdc1 at port 0x170-0x177 irq 15 flags 0xa008a008 on isa0 wdc1: unit 0 (wd2): WDC AC22500L, DMA, 32-bit, multi-block-8 wd2: 2441MB (4999680 sectors), 4960 cyls, 16 heads, 63 S/T, 512 B/S wdc1: unit 1 (atapi): CD-ROM TW 120D/V2.10, removable, dma, iordy wcd0: drive speed 2062KB/sec, 240KB cache wcd0: supported read types: CD-R, CD-DA wcd0: Audio: play, 255 volume levels wcd0: Mechanism: ejectable tray wcd0: Medium: no/blank disc inside, unlocked atkbdc0: keyboard controller (i8042) at port 0x60-0x6f on isa0 atkbd0: AT Keyboard irq 1 on atkbdc0 vga0: Generic ISA VGA at port 0x3b0-0x3df iomem 0xa-0xb on isa0 sc0: System console on isa0 sc0: VGA 16 virtual consoles, flags=0x200 sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 sio0: type 16550A sio1 at port 0x2f8-0x2ff irq 3 on isa0 sio1: type 16550A sio2 at port 0x3e8-0x3ef irq 5 on isa0 sio2: type 16550A ppc0 at port 0x378-0x37f irq 7 drq 3 on isa0 ppc0: Winbond chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode ppc0: FIFO with 16/16/16 bytes threshold lpt0: generic printer on ppbus 0 lpt0: Interrupt-driven port ppi0: generic
Re: ata vs wd driver performance
It seems Richard S. Straka wrote: I have recently performed some testing on the ata and wd drivers on my system. When writing to and reading from a file on the same file system in the same directory, the ata driver appears to take almost double the CPU time as compared to the wd driver. However, when reading from the raw disk, the ata and wd driver take about the same amount of CPU time. DMA is enabled in both driver. Since the old driver doesn't tell you which DMA mode it uses, its a bit difficult to compare, but my gues is that the wd driver set UDMA2 mode and from the ata probe it can bee seen it only sets WDMA2 mode. Besides you should upgrade your current, the ata driver has support for the VIA chip now... Can someone explain why the ata driver is using more CPU? Rich Straka [EMAIL PROTECTED] * wd driver results writing to a file. $ time dd if=/dev/zero of=test.dat bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 41.810011 secs (6420363 bytes/sec) real0m42.136s user0m0.002s sys 0m19.939s * ata driver results writing to a file. $ time dd if=/dev/zero of=test.dat bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 39.475358 secs (6800077 bytes/sec) real0m39.750s user0m0.008s sys 0m35.665s wd driver results reading from a file. $ time dd if=test.dat of=/dev/null bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 39.992958 secs (6712068 bytes/sec) real0m40.040s user0m0.025s sys 0m13.387s ata driver results reading from a file. $ time dd if=test.dat of=/dev/null bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 37.914618 secs (707 bytes/sec) real0m37.944s user0m0.009s sys 0m28.221s wd results reading from raw disk. $ time dd if=/dev/rwd0 of=/dev/null bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 33.100446 secs (8109723 bytes/sec) real0m33.137s user0m0.000s sys 0m0.266s ata results reading from raw disk. $ time dd if=/dev/rwd0 of=/dev/null bs=1024k count=256 256+0 records in 256+0 records out 268435456 bytes transferred in 34.518500 secs (7776568 bytes/sec) real0m34.535s user0m0.000s sys 0m0.222s *** dmesg with wd driver. *** Copyright (c) 1992-1999 The FreeBSD Project. Copyright (c) 1982, 1986, 1989, 1991, 1993 The Regents of the University of California. All rights reserved. FreeBSD 4.0-CURRENT #1: Sat Dec 4 09:22:58 MST 1999 Timecounter "i8254" frequency 1193182 Hz Timecounter "TSC" frequency 333189478 Hz CPU: AMD-K6(tm) 3D processor (333.19-MHz 586-class CPU) Origin = "AuthenticAMD" Id = 0x580 Stepping = 0 Features=0x8001bfFPU,VME,DE,PSE,TSC,MSR,MCE,CX8,MMX AMD Features=0x8800SYSCALL,3DNow! real memory = 134152192 (131008K bytes) avail memory = 127021056 (124044K bytes) Preloaded elf kernel "kernel" at 0xc0303000. npx0: math processor on motherboard npx0: INT 16 interface pcib0: Host to PCI bridge on motherboard pci0: PCI bus on pcib0 pcib1: VIA 82C598MVP (Apollo MVP3) PCI-PCI (AGP) bridge at device 1.0 on pci0 pci1: PCI bus on pcib1 isab0: VIA 82C586 PCI-ISA bridge at device 7.0 on pci0 isa0: ISA bus on isab0 ide_pci0: VIA 82C586x (Apollo) Bus-master IDE controller at device 7.1 on pci0 chip1: VIA 82C586B ACPI interface at device 7.3 on pci0 sym0: 875 irq 10 at device 8.0 on pci0 sym0: Symbios NVRAM, ID 7, Fast-20, parity checking sym0: open drain IRQ line driver, using on-chip SRAM vga-pci0: Matrox MGA 2164W graphics accelerator at device 9.0 on pci0 fxp0: Intel EtherExpress Pro 10/100B Ethernet irq 12 at device 10.0 on pci0 fxp0: Ethernet address 00:a0:c9:27:fc:1d fdc0: NEC 72065B or clone at port 0x3f0-0x3f7 irq 6 drq 2 on isa0 fdc0: FIFO enabled, 8 bytes threshold fd0: 1440-KB 3.5" drive on fdc0 drive 0 wdc0 at port 0x1f0-0x1f7 irq 14 flags 0xa008a008 on isa0 wdc0: unit 0 (wd0): IBM-DCAA-34330, DMA, 32-bit, multi-block-8 wd0: 4134MB (8467200 sectors), 8400 cyls, 16 heads, 63 S/T, 512 B/S wdc1 at port 0x170-0x177 irq 15 flags 0xa008a008 on isa0 wdc1: unit 0 (wd2): WDC AC22500L, DMA, 32-bit, multi-block-8 wd2: 2441MB (4999680 sectors), 4960 cyls, 16 heads, 63 S/T, 512 B/S wdc1: unit 1 (atapi): CD-ROM TW 120D/V2.10, removable, dma, iordy wcd0: drive speed 2062KB/sec, 240KB cache wcd0: supported read types: CD-R, CD-DA wcd0: Audio: play, 255 volume levels wcd0: Mechanism: ejectable tray wcd0: Medium: no/blank disc inside, unlocked atkbdc0: keyboard controller (i8042) at port 0x60-0x6f on isa0 atkbd0: AT Keyboard irq 1 on atkbdc0 vga0: Generic ISA VGA at port 0x3b0-0x3df iomem 0xa-0xb on isa0
