800mh w/ 100FSB running 133MH memory?

[fragger55]

My 800MH PIII Slot 1 Processor only has a 100MH FSB and does not support 133. If I buy 133MH Memory will it run at 100MH because that is what my Processors FSB is running at? Must the Processor FSB and Memory speed be the same? My Asus P3V4X CMOS settings say 800/133.

 

[Doomsday]

Ya, the 133Mhz memory will run at 100MHz. All that number means is its "safest" maximum speed setting for the FSB. I've got a friend that has 100MHz RAM, and is able to run it at 127MHz. As for the CMOS setting, that's just screwed up.

 

[Windogg]

Be sure to run it at 2-2-2 @ 100Mhz for maximium performance.

Windogg

 

[DaddyG]

The answer to your question depends on the chipset that your mobo runs. Mobos based on VIA Apollo Pro chipset feature a memory bus which can operate at FSB + or - the PCI bus giving a max of 133 for 100 fsb.

 

[Sugadaddy]

I'm pretty sure you can run your ram @133 while you cpu runs @100mhz fsb on the p3v4x. There should be a setting in the bios...

 

[Howard]

The FSB and memory clock must always be the same. It's not like you can change it anyway. Your processor gets the speed it's supposed to run at by multiplying the FSB by the multiplier that it reads from the core. So yours would be 8 x 100 = 800MHz.

Your processor does support PC133, the FSB just doesn't run at that speed. If you overclock the FSB to 133MHz, then your processor would run at 1046MHz. However, you stand little chance of achieving that speed.

 

[AngelOfDeath]

You should be able to do 100 fsb with the cpu and 133 with the ram with that mobo

AoD

 

[dszd0g]

Since, people are going back and forth in this thread. I thought I'd put my opinion in. My guess is all the people in this thread who say that the FSB and memory speed must match have only been using Intel chipsets. The Via Apollo Pro 133A, KX133, and KT133 all support memory +/- 33Mhz in the BIOS. With one of these mobos like your Asus P3V4X you can have the FSB at 100Mhz and the memory at 133Mhz.

If you start overclocking your FSB it starts overclocking your memory too. For example if you were running the FSB at 110 it would be running the memory at 143 if you had the memory set to +33Mhz. Some PC100 memory can overclock to 133Mhz. Some people have had luck overclocking PC100 CAS2 to 133Mhz CAS3. Some people can get their PC100 CAS2 to PC133 CAS2. Some people have gotten there PC133 CAS2 up to 150Mhz CAS3.

 

[rmblam]

Yeah what he said.

Synchronous = memory and bus at same speed.
Asynchronous = memory and fsb independent.

CHeck your BiOs

 

[AngelOfDeath]

More or less what I said just a bit shorter

AoD

 

[Slacker]

<< My Asus P3V4X CMOS settings say 800/133 >>



Hmmm..... It sounds like you have an 800EB which runs on the 133mhz front side bus, an 800E would run on the 100mhz front side bus.

 

[Doomsday]

I'm back again, just to clarify, you can put the 133 MHz on the board, it won't run at the full 133 MHz, it will only run at the 100MHz,because that's that the FSB is set at. If you increase the FSB, say up 5 for 100 making the processor running 5% faster at a 105 FSB, then the RAM would run at 105 MHz. The FSB, and the RAM setting have to be the same, but just because the RAM says 133 MHz, doesn't mean that it JUST runs at 133MHz. I have 133 MHz RAM and I run it at 100MHz, because that what my FSB is at.

 

[Sugadaddy]

Doomsday, you might want to read a little more info before you post false statements. Like a couple of us have been saying, you can run an asynchronous fsb and memory bus with the newer Via chipsets, which happens to be on the p3v4x (apollo133a)

 

[dszd0g]

Slacker, I assumed he had an 800E and not an 800EB because he said his processor only supported 100Mhz. I kind of missed the 800/133 thing. fragger55, do you have an 800E or 800EB? If you have an 800EB any mobo that supports 133Mhz can use PC133 memory with that processor. You could even overclock a BX to BX133 which works great.

You have an Asus P3V4X. If you have an 800E, you need to have the memory in the BIOS set to 3/4 for memory to be at 133Mhz. If you have an 800EB, you have it set to 1/1. Under Advanced menu you should see your CPU speed 800Mhz (or Manual), if you have an 800E the &quot;CPU: System Frequency Muliple&quot; will be 8.0x. If you have an 800EB it will be 6.0x. For a non overclocked system a 800EB should have &quot;System/PCI Frequency (Mhz)&quot; set to 133.9/33.25 and an 800E should have approximately 100/33. Then you set System/SDRAM Frequency Ratio as above to either 1/1 or 4/3 depending on the processor and memory you are running or even 4/3 if you have a 800EB and you want to use PC100 memory. I think I have the order right as far as System/SDRAM please double check that it isn't SDRAM/System.

 

[dszd0g]

AngelOfDeath:



<< More or less what I said just a bit shorter >>



Yeah, a few people stated what I did before me in different words. As I said, I was just sharing my opinion, because there are differing opinions in this thread (like Doomsday.)