DMA, new VIA mobos, and the old MVP3

[Sudderth]

My brother and I have Socket 7 MVP3 motherboards, he one of the last Epox models with DMA-66 and me a piece-of-(deleted) TMC motherboard (for which TMC hasn't provided a BIOS update since '99).

Both of us have problems getting the motherboard to recognize the DMA mode of our CD burners (his is a Panasonic CD-RW, mine is a Toshiba SD-R1002 combo drive). Instead they boot in PIO Mode 4.

I figure this is a limitation of the MVP3 chipset, but since I'm in the market for a new motherboard/CPU, I'm wondering if anyone has had any DMA problems with the current generation of Socket A VIA chipsets. I'd rather get an Athlon than a Pentium III, but the cost savings would be negated if I had to suffer through choppy DVD playback, and having tried my drive in a couple of older Intel boxes I'm confident that Intel chipsets wouldn't have a problem....

Thanks,
Sudderth

 

[Peter]

Nope, nothing to do with the north bridge. Install VIA's latest IDE drivers, and then verify from their DMATOOL.EXE the mode you're actually running at.

Most older BIOSes don't run the drives in any DMA mode for DOS - it's up to the operating system's own drivers to enable it. The Epox board is one I personally know, and its UDMA66 performance is definitely there. Use the latest BIOS and fresh drivers.

Regards, Peter

 

[Sudderth]

Well, I can't speak for my brother's Epox board, but with my TMC board, neither Windows' natural DMA settings nor the VIA 4-in-1 would work.

During POST, before the master HD's OS kicks in, the BIOS lists the drives it's found. It recognizes my ATA-66 HD, an older ATA-33 HD, and my CD-ROM as DMA devices. But it lists my combo drive as "Mode 4." After many tests and grumblings, yanking out drives and replacing them in interesting combinations, the drive wouldn't come out of POST with the magic letters "DMA" next to it.

VIAs Busmaster drivers were of no help; the boxes in DMATOOL remained stubbornly grayed-out.

(I plugged the combo drive into a Dell system, and everything came up roses, so I don't think it's the drive.)

So I really think this is a motherboard-level issue. Or am I missing something?

And (the big question) is there any reason to believe that any modern Athlon or P3 motherboard would have issues with recognizing a combo drive as DMA-capable?

 

[Peter]

Well, some BIOSes don't report the active DMA mode on the second screen, nevermind that.

When DMATOOL shows its checkboxes greyed out, it indicates that VIA's IDE drivers are not active. Getting rid of Microsoft's own drivers sometimes is really difficult. Follow the instructions that come with the VIA drivers.

Regards, Peter