Hardware reports PIO instead of DMA on disks (asus a7n8x mobo, w2k)

[Al Dykes]

Why isn't my system runnning my disk in DMA ? I can't see where this
is set in XP.

It's an A7n8x modo with an 80GB EIDE disk and a 160GB SATA disk. Each
on it's own channel. CPU is an AMP Athlon 2200.


HDtach 2.70 reports:

50MB/s max @ 28% CPU on the 80GB disk
63MB/s max @73%CPU on the 160GB disk

The last time I screwed with DMS vs PIO was several years ago and
at that time I found DMA was better, and SCSI got CPU % utilizization
down to single digits. 73% on the SATA channel doesn't sound right.


Any suggestions ?

Thanks

-----------------------------------------------------------------------

WD 80GB EIDE Disk:
Model ID WDC WD800JB-00CRA1
Parameters 155061 cyl, 16h, 63sec
LBA Sectors 156301488
Buffer 8 MB
Dual Ported, Read Ahead
Multiple Sectors 16
ECC Bytes 40
Max. PIO Transfer Mode PIO 4
Max. UDMA Transfer Mode UDMA 5 (ATA-100)
Active UDMA Transfer Mode UDMA 5 (ATA-100)
Unformatted Capacity 89436 MB

Maxtor 160GB SATA DIsk:
Model ID Maxtor 6Y160M0
Parameters 317632 cyl, 16h, 63sec
LBA Sectors 320173056
Buffer 7936 KB
Dual Ported, Read Ahead
Multiple Sectors 16
ECC Bytes 4

Max. PIO Transfer Mode PIO 4
Max. UDMA Transfer Mode UDMA 6 (ATA-133)
Active UDMA Transfer Mode UDMA 5 (ATA-100)
Unformatted Capacity 156334 MB

 

[GTS]

According to the stats you posted, both drives ARE using ATA-100 mode, see
"Active UDMA mode"
So don't think you have any problems, apart from the CPU usage - how are you
measuring this? I use SiSoft Sandra but it does'nt give CPU usage for the
HDD benchmarks...

 

[Papaboojum]

Why isn't my system runnning my disk in DMA ? I can't see where
this

is set in XP.

To check the Windows XP setting: Open Device Manager, expand the IDE
devices item, then open a Properties dialog on the IDE channel where
your HDs are installed, most likely Primary. On the Advanced tab
check the Transfer Mode setting, it should be set to 'DMA if
available'.

Did you recently install SP2? I ask because I had XP switch to using
PIO mode on IDE devices (in my case an NEC DVD-RW drive on my Seconday
channel) where DMA mode worked fine pre-SP2. I don't yet know if its
a bug in SP2 or an incompatibility with something in my system.

 

[Al Dykes]

To check the Windows XP setting: Open Device Manager, expand the IDE
devices item, then open a Properties dialog on the IDE channel where
your HDs are installed, most likely Primary. On the Advanced tab
check the Transfer Mode setting, it should be set to 'DMA if
available'.

Did you recently install SP2? I ask because I had XP switch to using
PIO mode on IDE devices (in my case an NEC DVD-RW drive on my Seconday
channel) where DMA mode worked fine pre-SP2. I don't yet know if its
a bug in SP2 or an incompatibility with something in my system.

Thanks

This is w2k.


The primary IDE is listed as "DMA if available". That's the 80GB disk.

The SATA driver is under SCSI Devices and it doesn't allow any choices.

FWIW It's a Silicon Image 3112 controller.

I still don't understand what's going on.

 

[root]

Why isn't my system runnning my disk in DMA ? I can't see where this
is set in XP.

It's an A7n8x modo with an 80GB EIDE disk and a 160GB SATA disk. Each
on it's own channel. CPU is an AMP Athlon 2200.


HDtach 2.70 reports:

50MB/s max @ 28% CPU on the 80GB disk
63MB/s max @73%CPU on the 160GB disk

The last time I screwed with DMS vs PIO was several years ago and
at that time I found DMA was better, and SCSI got CPU % utilizization
down to single digits. 73% on the SATA channel doesn't sound right.


Any suggestions ?

Ignore HDTach's CPU usage figures. The transfer rate is what it is good at.
It is using UDMA mode.