View Full Version : about the 64bit 66mhz pci slots...

10-27-01, 05:08 AM
would i beable to run a pci vid card at 66mhz? i realize it depends on the card but what i really mean is liek would it let me try cuz i know its backwards compatible with th 33mhz slots too

10-27-01, 05:25 AM
it would depend on the mainboard you had. there are 64bit PCI slots and there are 64/32bit PCI slots. i would guess you can figure out what the difference is. i will admit i have never actually tried what you are asking (as a matter of fact i have only reached into a box with 1 64/32bit PCI slot. nothing like some of the high end server boards which have multiple 64bit compatable PCI slots). i would paruse the board's detailed specs and look for something that states the actual compatabilty of the slot(s). i would assume if its a 64bit only-commpatable slot, then i would say "no". a 64bit I/O can be designed to run in 32bit mode, but only if it is designed to do so (software and hardware alike).

10-27-01, 05:48 AM
ok i'll be more direct still, in a 32/64 slot could i run it in 32 mode at 64 speed? or is it all one option?

10-27-01, 06:00 AM
no. if its a 64bit only slot it will not run unless your PCI card is designed to run in 64bit mode.

if its a 64/32bit slot. then yes.... it will run in 32bit mode.

10-27-01, 06:13 AM
actually, let me clarify..... 64 bit mode and 66MHz PCI bus are two different things (though one is a specification within the other, but not dependant on the other as far as whas possible in computer terms. 64bit is the block size of the data sent at one time, and 66MHz is the frequency/speed of the data transmitter/reciever of the host).

in other words, unless you have a vidcard which will run in 32bit mode at 66MHz and be able to move data in 64bit chunks, you are out of luck. unless the PCI slot is also able to run in 32bit mode (at 33MHz as well). and then it will be a 32bit only interface... not 66MHz or 64bit.

10-27-01, 06:17 AM
what i have is a car that will run 32 bit mode and is running at 33mhz i was wondering if i could run it in 32 bit mode at 66mhz if i have a mobo with a 64 bit slot since it would allow for the 66 mhz option then

10-27-01, 06:25 AM
if your "car" can run at 66MHz then yes (if you can OC the PCI bus by that much). remember.... 64bit data block. a device running in 32bit mode wont be able to read it. i personally dont know or havent run across an instance where i saw a 32bit/33MHz cards running at 66MHz. many card dont like a speed over 40MHz.

10-27-01, 06:29 AM
Originally posted by smaier69
if your "car" can run at 66MHz then yes. i personally dont know or havent run across an instance where i saw a 32bit/33MHz cards running at 66MHz. many card dont like a speed over 40MHz.

meant card, thats cool i was just hoping its an option, not much else i can try for pci OCing.

10-27-01, 06:34 AM
no problem. i edited the post while you were posting.

i am confused now. too many beers will do that you you.

i am pooped.

(*crawls into the spot he will pass out in. that being me*).

10-27-01, 12:33 PM
Most 32Bit PCI cards are designed for 33Mhz, so 66Mhz is wayy too much.

10-27-01, 01:15 PM
also depends on the quality of all your other PCI devices. I know most are all designed for only 33mhz and any above that craps them out and gives you BSOD.I guess that's why they made the AGP port, independent of the PCI for increase peformance and could be clock to a high mhz cycle.