Enabling DMA

My CD ROM and CD R-RW are running (and have been running for a long time) in DMA mode with no problems.
Is there any REAL advantage to have the hard disk run in DMA mode?

 

Ace
Fred Langa has some thoughts on DMA at
http://www.langa.com/newsletters/2001/2001-01-18.htm

 

I just checked my BIOS and I see "Ultra ATA DMA mode" but it's not highlighted, I can't access it. Could this be because I don't have it enabled in device manager?

I'm running Win 98SE on a relatively NEW system, put together just 7 months ago. (WD 30GB HD 7200 RPM, Asus CUSL-2C motherboard)

 

Here's Microsoft's thoughts on enabling DMA.

http://www.microsoft.com/hwdev/archive/devdes/idedma.asp

Dale

 

I enabled DMA for my HD. After rebooting the check mark is still next to DMA enabled.....Can I safely assume that it is IN FACT enabled?

 

if the check mark is still there, it is enabled

 

Watch your bios screen at startup

I have the same board. Watch your bios screen at startup. I have DMA checked in Device Manager settings and it made a huge difference. Bios shows my hard drives at UDMA 5.

 

In order to read the information at boot up, do I press "PAUSE" to stop at a particular section? If so, pressing "PAUSE" again should continue the boot process?

 

I hit Pause to stop it, Enter to continue. There might be another way, but's that's how I've done it.

 

Thanks! I was able to check at boot up and it lists my HD at Ultra DMA 5.

Hope you don't mind another question. My CD ROM and my CR R-RW drives both have DMA enabled but at the boot up screen it lists these devices at "Mode 4" is this correct for these type drives in DMA mode?

I have a Ricoh CD R-RW drive which recommends you run it in DMA mode so I know it's compatible with DMA.

 

Walt, it could be the chipset drivers, storage drivers, etc. I only install the chipset drivers and avoid everything else for this board.
My CD-Rom will not keep the DMA setting in Windows, with only the chipset drivers installed. It does, however, show UDMA 2 in the bios screen. My CD-RW is supposed to be set on PIO mode, according to HP, so that's where I left it.
Apparently, the installation of the ATA Storage Drivers from Intel can cause some problems with regard to CD-Rom and CD-RW drives.

Maybe someone at asusboards.com can be of more assistance.

In any event, the faster these CD-ROM drives get, the slower they seem to work. And they sound like a 747 starting up. My old 4x worked better.

 

Evinrude,

I installed the chipset drivers for my mobo as instructed right after Win 98SE was installed and BEFORE any apps were installed.

What's strange about my situation is that in windows Device Manager it shows DMA enabled for my HD, CD ROM and CD R/RW but in my BIOS only my HD is DMA enabled my CD ROM and CR R/RW shows PIO 4 mode. Everytime I go in the BIOS and change the CD R/RW to DMA when I go back to the BIOS to check it's gone back to PIO mode yet it remains DMA checked in windows Device Manager.

Could this be due to the fact that my Mshdc.inf file does NOT have those two lines in it....see link for this:
http://www.microsoft.com/hwdev/archive/devdes/idedma.asp

 

I tried adding those two lines but nothing changed.

If you have only added the chipset drivers and the bios info shows your hard drive(s) at UDMA 5, that's good.

Your CD-RW may not want to run in other than PIO mode.

Your CD-ROM, if it's like mine, will show something like UDMA 2 in the bios screen. If it doesn't it may be due to the requirements of that particular CD-ROM drive. Mine is an Asus 50x and that's what I see when viewing the bios screen.

FYI: I have 2 HD's. Main on is master on IDE1, second one is set as slave. Both show as UDMA 5 in bios screen.

My CD-ROM is master on IDE2 and the CD-RW as slave, as per the recommendations of HP. Everything works fine for me like that.

 

Evinrude,
UDMA won't remain selected in my BIOS for my CD ROM and CD R/RW drives because the BIOS lists the UDMA not DMA. I wonder if this could be the difference......between UDMA and DMA that's whey it doesn't stay activated in the BIOS, HOWEVER my CD ROM and CD R/RW drives do remaind DMA active in Device Manager.

While I don't have this problem, I ran this debug test (http://support.microsoft.com/default.aspx?scid=kb;EN-US;q159560) to make sure my CD ROM and CD R/RW drives are DMA compatible and according to the test results they are. Once again there's a difference in wording here DMA as opposed to UDMA. So perhaps the reason my CD ROM and CD R/RW drives remain DMA checked in Device Manager but NOT in my BIOS is due the to difference between DMA and UDMA.

Just trying to completely troubleshoot this situation here.