Running AMD K6 at 66Mhz instead of 100 Mhz

[labrador]

Given the high price of RAM right now I'd rather wait on getting my SDRAM upgraded to PC100 RAM. However getting the 266 Mhz AMD K6-2 upgraded to something like a 400 or 450 is something I'd like to do. Can I run the AMD K6-2 400 with a multiplier on 66Mhz or does that just fizzle?

Couldn't find the answer at AMD's web site.

[acobra]

You should be able to set the FSB to 100 and still set the memory to 66.

There should be a SDRAM multiplier which you can set to 2/3 FSB. I know the FIC VA503+ and the Epox MVP3G2 both allow this, I'm sure other boards do as well.

I see no reason why you CAN'T set your clock speed to 66, but I doubt you have a 6x multiplier, so you would be underclocking... (6 x 66 = 396).

If you do have a 6x multiplier setting your computer would be evil (666) anyway and would never work right!! LOL.. I crack myself up sometimes.

Good Luck!

[Wombat]

Yes, the VIA MVP3 chipset supports asynchronous RAM/CPU-bus timings. You could run the chip at 4x100 and the RAM at 66Mhz, though it wouldn't be nearly as fast as having a full 100Mhz FSB.

-Wombat



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K6-2/350@400, 503+ rev 1.2a, 128MB PC100 RAM, Millenium G200, RH6.1 w/ 2.2.12-20, Win98, and too many classes

[labrador]

Thanks for the answers, peoples!

However the motherboard is an Asus P5A, and I don't think it has separate jumpers for the RAM timing. I remember seeing something about asynchronous motherboard settings in a Tom's Hardware review of the then new super 7 motherboards. The review mentioned that this was useful for overclocking experiments but I wasn't interested in that.

You might be right about the 6x not being available - it seems to stop at 5.5 times
which would allow 366Mhz. Another possibility is trying 95Mhz bus speed, but that is very close to 100 and probably won't work.

[acobra]

According to the manual for your MB, you should be able to set a 6x multiplier...

It does say in your manual not to use 66mhz memory unless your clock speed is set below 95, so I guess unless you get new memory that is your best option (6x66)...

Memory prices have come down a LOT though, Price watch now shows $127 for the cheapest 128meg PC100 right now... same thing was $250 a few weeks ago.

[SteveC]

Just try 100mhz FSB - your RAM may well suprise you and run fine at 100mhz. If not, the K6-2 will run fine at 66mhz bus.

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Cheers,
Steve

"The chances of anything coming from Mars, are a million-to-one", he said.

[paul]

I tried running a k62-350 on a 66/75/83 mb and it never made it to the desktop.

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k6-3 450 @500 - tyan 1590s bios 1.16 - wdac310100 - g200 mill sgram w/8mb upgrade & bios 2.6-20 PD 5.25 - AGP1x - 128MB 10ns sdram - sblive value 2.1 - 3com 3c905b-tx - cable access (28.8k for emergencies) - win98 service pack 1 + 2
dx7

[labrador]

For the record, the AMD K6-2 400Mhz requiring 100 Mhz bus speed worked OK with the old SDRAM memory. At this point I've run benchmarks and flight sims and it seems OK. Funny thing is that this memory is just the cheapest memory available at the time in an SDRAM configuration. Two 32 MB segments and one 8 MB, all different markings on the DRAMs.

Thanks for the help, peoples...