I put PC100 RAM in along with PC133 RAM in a machine w/133FSB

[eLiu]

Hey all,
This is in a Dell Dimension 4100, P3 866 with 133FSB.

It came with 128MB of PC133 RAM...I stuck in another 128MB stick of PC100. The machine booted fine and BIOS recognized one stick as PC100 and the other as PC133.

During POST, it reports 256MB of total ram & still reads the CPU speed as 866mhz with 133mhz FSB...

So my question to you folks is: is the computer actually running at 133fsb? Is it actually using both sticks of RAM?

I would check this, but I'm installing linux right now... I plan on running memtest86 later on, but I was wondering if any of you know the answer.

Thanks,
-Eric

 

[Remedy]

Your highest DRAM clock is dependent on the slowest product on the BUS. Which is, the PC100. PC133 can and will down clock itself to lowest common frequency. PC100, will not clock to 133Mhz.

 

[CrispyFried]

run everest if you still have windows loaded, it will tell fsb and ram speeds.

 

[LTC8K6]

I would guess that the Dell either doesn't like the ram, or it is trying to run it at 133.

 

[eLiu]

Originally posted by: ReMeDy{WcS}
Your highest DRAM clock is dependent on the slowest product on the BUS. Which is, the PC100. PC133 can and will down clock itself to lowest common frequency. PC100, will not clock to 133Mhz.

I didn't think any pentium 3 boards had asynchronous clock rates (i.e. the entire fsb goes down to 100, meaning the CPU slows down too). Are you saying that you know that the entire FSB will drop to 100mhz?

CrispyFried, nope...don't have windows on it.

LTC8K6, I'm hoping it's trying to run it at 133mhz. IIRC there were many PC100 sticks that would run at PC133 speeds. At least I & people I've talked to have had some successes doing this.

 

[jjsbasmt]

Some PC100 ram will run OK at 133, but you can never tell from stick to stick. I've seen a lot of systems where someone has done that RAM mismatch, in fact I worked on a Gatewaay Athlon 700 last week with that problem. Aslo for your info, some PC133 RAM is designed to clock down to 100 with no errors, and some is specifically made not to clock down.

 

[eLiu]

Originally posted by: jjsbasmt
Some PC100 ram will run OK at 133, but you can never tell from stick to stick. I've seen a lot of systems where someone has done that RAM mismatch, in fact I worked on a Gatewaay Athlon 700 last week with that problem. Aslo for your info, some PC133 RAM is designed to clock down to 100 with no errors, and some is specifically made not to clock down.

mmm I guess there's no easy way of telling of the Dell dropped my FSB to 100 or if it is running the PC100 stick at 133 speeds...darn, lol

 

[CrispyFried]

The p3 is multiplier locked so if it posts as a 866 the fsb is still 133.

ram may or may not be at 133 though. some pc100 can handle 133 so you may of gotten lucky.Im pretty sure Ive seen some intel boards run a 133 fsb with 100 ram too. so flip a coin

 

[bob4432]

Originally posted by: CrispyFried
The p3 is multiplier locked so if it posts as a 866 the fsb is still 133.

ram may or may not be at 133 though. some pc100 can handle 133 so you may of gotten lucky.Im pretty sure Ive seen some intel boards run a 133 fsb with 100 ram too. so flip a coin

cpu-z

 

[rstrohkirch]

Via boards were the only ones that I recall allowing you to run p3 systems async with the options -33/host/+33
Since he's using a dell he'd be running an intel board resulting in sync'd and the system running at 133mhz

 

[LTC8K6]

I have a Dell L667r that runs a 133fsb and ram at 100. It has been upgraded to a P3 1Ghz/133 chip and the ram is still locked at 100mhz. It's an i810 chipset board. The board is quite picky about having cas2 PC100 in it. PC133 just runs at 100 also.

You can run CPU-Z to tell you what is running at what.....

 

[rstrohkirch]

Originally posted by: LTC8K6
I have a Dell L667r that runs a 133fsb and ram at 100. It has been upgraded to a P3 1Ghz/133 chip and the ram is still locked at 100mhz. It's an i810 chipset board. The board is quite picky about having cas2 PC100 in it. PC133 just runs at 100 also.

You can run CPU-Z to tell you what is running at what.....

You're quite correct, starting from the i810 intel added the abilityto run an asynchronous bus.
I stand corrected

 

[eLiu]

hm I guess I'll find cpu-z for linux & have a look...