UDMA problems

[dimi]

Hi,
I have recently ubgraded my p2b (rev. 1.04) motherboard using a slotket
with a CeleronII 633 overclocked to 800 (Put the voltage on 1.8V and the
FSB to 88Mhz, it freezed during startup when I put it to 100 MHz). My
BIOS rev. is 1012.
I have a IBM 8GB HD, a BTC 32x CDROM and a Liteon 24/10/40 CD-RW as
master on the second ide controller. I also use a Sounblaster AWE 64 for
sound. My OS is W98. I system has a 300W p/s.
My problem is that recently I read in a magazine that enabling the, DMA
(checking the box) will speedup my drives. So I went to the HD
properties of the HD and CDROM and enabled it (it was unchecked). In my
specs all drives were listed as UDMA2 compatible and so says the BIOS
during startup.
When I rebooted my maschine, I got regularl terrible lockups which would
last for 1-2 secs.The sound also got lock up and repeated itself. In the

SisoSoft Sandra tests the HD is performing faster than before, but when
I run any game or app, I get lockups. Its like the HD and sound gets
stuck for a few
seconds and then continues. When I uncheck the boxes I get according to
the benchmark only UDMA performance but the system runs smoothly.

Hope you can help.
Thanks in advance.

[hiredgoonz]

You probably don't want to hear this, but try running the chip at 633mhz with UDMA enabled and see if the problems are still there...

If it works properly, then the overclock is the problem...at 88mhz fsb, you're running everything WAY out of spec...the divider for the PCI bus on that system should be 1/2, so you're running devices designed for 33mhz at 44mhz...not good...

At slower transfer speeds (non UDMA) the devices may be able to handle the overclock, but become less tolerant at higher speeds...

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