Plextor DMA on ASUS A7V ->Plextor Support Team->Not Possible

[Hardware]

> PIO Mode 3 with DMA on = DMA Mode 0
> PIO Mode 4 with DMA on = DMA Mode 1
> UDMA/33 with DMA on = DMA Mode 2
> UDMA/66 with DMA on = DMA Mode 4
> UDMA/100 with DMA on = DMA Mode 5



Best what you can get is PIO Mode 4 with DMA on = DMA Mode1

I am not sue which os support this. Win2000 do not support DMA Mode 1

 

[WetWilly]

From the horse's mouth at Plextor:

Burst Read/Write: 16.6MB/sec (PIO Mode 4/DMA Mode 2)

Check it for yourself here: Plextor 12/10/32A Specifications PDF

Note that all DMA modes aren't Ultra DMA (there's single word and multi-word DMA as well as Ultra DMA), therefore DMA 2 isn't the same as Ultra DMA 2. The Promise Ultra 100 makes the distinction on boot, e.g. my Plextor 12/10/32A is DMA 2, but my ATA/33 Maxtor drive is Ultra DMA 2.

 

[brianafischer]

Nicely Put.

 

[stealthy]

WetWilly,

It seems that you are right on spot here. I installed the plextor on an older computer which I own (Asus TXP4). I runs flawlessly !!!!!!!!!!!!!! DMA checked ! I tried it under Win2000 and Win98. It worked perfectly. I'm almost sure this is an Asus related problem. I suspected problems with the ATA66 controller because I experienced quite some problems the past days. Random lock-ups when accessing other drives. Data corruption when doing intensive calculations. Needed already to re-install Win NT ...
This board will be history starting off tomorrow. I'm going to buy the Abit KT board. I have had it with this board

 

[WetWilly]

Stealthy,

Unfortunately, Asus seems to have stumbled a bit with the A7V. I know people have been getting good results with them, but they seem to have a higher amount of "weirdness" associated with them than you'd typically find with an Asus product. Have you tried any of the newer/older A7V BIOSes around? If you're determined to get rid of the A7V, I (and several others here) can heartily recommend the Abit KT7. I've been almost stunned by how stable it is - right up there with the BX boards I've worked with, and definitely better than the Apollo Pro boards. In fact, I went from a BX board to the KT7 in less than an hour with no problems at all. My Duron 700 is running at 978MHz (8.5x115MHz) like a champ (unless I access my old ATA/33 Maxtor drive which doesn't like an OC bus - so I don't access the drive often ). If you're thinking of getting the RAID version, read this thread Once again.... Abit is a major let down for me about why I don't care for the onboard RAID.

Good luck.

 

[Atroz]

HI,

I was wondering if you've had any luck getting the plextor going on the A7V with DMA? Any chance that the latest 1.004c BIOS fixes this problem? Or perhaps a Plextor firmware update?

I was looking buying this drive, but I also have an A7V motherboard.

Thanks.

 

[stealthy]

Well,

Tried all the plextor Firmware upgrades, 3 versions of the Via drivers, upgrades 3 times mij MB bios (currently 1004a) not luck whatsoever ! Really I've had it with this board.
Last week I have had so much problems with the board. Two weeks ago I thought my problems where solved. In the beginning my Videoboard wasn't recognized. The some of my ram-sticks weren't recognised ... But after last week ...
E-mailed for about 1 week with Plextor support. They couldn't find the problem either. It is supposed to run in DMA mode 2. I promised them to keep them the drive once it will be installed in the Abit board

 

[stealthy]

Wet Willy,

Purchased the Abit KT board. ALL PROBLEMS SOLVED !!!!! DMA support on the Plextor 12/10/32 works flawlessly. My Thunderbird 700 is even stable at 900Mhz ! On the A7V I hardly got it stable on 750Mhz. The only problem is that I can't do FSB overclocking. For some reason I get random lock-ups.
Small question on the DRAM clock. In the Bios they mention, DRAM frequency Host clock+PCI clock. Can I assume that this Host clock is equal to the FSB ? If not how can you OC the DRAM frequency ?

 

[Atroz]

Stealthy,

With the change from the Asus to Abit boards, what difference have you seen as far as the Plextor drive goes? I.e. what difference did getting to enable the DMA mode make for you? I assume the CPU usage went down, but has that impacted you in anyway?

Thanks.

 

[WetWilly]

Congrats. Another satisfied Abit customer .

Limited FSB overclocking with the Thundebird/Duron is pretty much a fact of life. My Duron 700 runs at 978 (8.5x115) just fine, but that's definitely more of an exception than the rule.

<< Small question on the DRAM clock. In the Bios they mention, DRAM frequency Host clock+PCI clock. Can I assume that this Host clock is equal to the FSB ? If not how can you OC the DRAM frequency ? >>

The Host Clock is the FSB. The only overclock option for memory is HostClk+PCI. Again, the catch is that your memory must be able to handle a minimum of 133MHz.

If you're trying to overclock the FSB, set all of your memory options to fail-safe first to ensure that your problems aren't caused by pushing the memory too far. Also note that you shouldn't rely on absolute Mhz numbers to determine your optimal result. For example, I can run at 1GHz (10x100MHz) just fine. Sounds good, but 978Mhz (8.5x115) is noticeably faster. SiSoft Sandra 2000 numbers (both with memory at HostClk+PCI):

1GHz (10x100): 501 ALU/565 FPU
978MHz (8.5x115): 562 ALU/653 FPU (Note that at 115MHz HostClk+PCI is 153MHz)

 

[office boy]

Sigh.... I read this, and UPS say's my A7V is to be delivered tomorrow...

 

[Hardware]

First set the Plextor as a single master drive
win2k gives me now dma on!

 

[Skooch]

If you read my earlier post to this thread, I also have the drive set as single master on the ATA66 controller, so my guess is that DMA functionality on the A7V is related to the drive's master/slave settings.

 

[stealthy]

What you did could indeed solve maybe the problems for you but it didn't for mine.
Believe me I've tried ALL kinds of settings. Ranging from single master drive to ... No solution for me. It was not only the DMA issue that concerned me. From time to time I got coasters for whatever reason. Further, accessing one of the drives (HD, CD-ROM, CDRW) resulted from time to time in random lock-ups, lost partitions, .... This computer will be used to do stress analysis in constructions. The program used puts quite some stress on the machine. Running some intensive calculations almost always resulted in lock-ups.
I'm running now the ABIT board. No problems anymore. It's rock solid. I'm not a particular advocate of Abit boards. In fact it's my first one. But I believe that Abit did a very good job with this board. My opinion