845G Chipset Memory Problem???

[Jola]

Many users of the P4B533-V motherboard, including myself, have had problems with this motherboard running memory at high speeds (+160MHz) at CL2. Many of the problems have been with Corsair XMS, but this has also happened with other brands. With this motherboard you have to run memory at 2.5-3-3-6 at the higher clock frequencies, irrespective of the quality of the memory.

The conclusion to be drawn from this is that there is little sense in buying good memory for this board (eg Corsair XMS3200C2) because the board simply can't use it.

Ram Guy at Corsair support is certain that there is no problem with the Corsair memory, and some users have also tried different modules/motherboards, with no success.

Now: Is this a P4B533-V problem (ie an ASUS problem), or is is a 845G problem (ie an Intel problem)?

Can any users of other 845G motherboards please comment? We need to pin down the cause of this problem.

 

[Odeen]

I have a stick of Samsung PC2700, on a 3rd party PCB, that the P4B533-V ran at 166mhz CAS2 - 2-2-2-5 timings with 2.7v ram voltage.

This was CPU limited, as I couldn't raise vcore over 1.725v without the board sounding the alarm..

 

[Jola]

Interesting, that seems to point back at the Corsair memory as being the problem! There is no way that I can achieve that at FSB=140 at 4:5 (memory at 175MHz) with my 512Mb Corsair XMS 3000C2. Or even at 165MHz memory speed!

Unfortunately my 1.8a doesn't like going over FSB=140. Which I can accept, but if I have to run 185MHz CL2 memory at low speeds, I want to run it at CL2!!!

Unfortunately I don't have other sticks that I can use to compare. That would be the only way to be sure, but I don't want to spend big cash just to prove a point!.

 

[canadianpsycho]

Corsair XMS3000CAS2 @ 147 MHZ FSB, 4:5 ratio (184 MHz) by SPD (2-3-3-6) on an EPoX 4G4A+ (i845g chipset)

I'd say the blame might lie upon Asus.

 

[Jola]

Must say, I am quickly running out of theories here. Every time that there seems to be a way of identifying the cause of the problem then someone pops up to shoot it down.

Odeen, you are running the memory at 166MHz CL2. But what is your FSB frequency? Are you running a "B" chip at FSB=166MHz and a 1:1 memory ratio. If this is the case then maybe the problem is with the 4:5 ratio on the P4B533-V. I state this specifically with respect to this motherboard because not all 845G boards seem to have this problem. Although there are reports of Abit 845G problems as well.

So: Is the problem with the 4:5 ratio - and therefore the reason why it pops up so often on the P4B533-V is because Asus have disabled the 3:4 ratio. With other motherboards most users would use 3:4, and wouldn't even notice that there is a problem with 4:5???

Someone please confirm or shoot this down!

Late Feedback:

Have done some tests at 3:4 at FSB=132 - Also problems!

This is not related to 4:5 - it is just a general problem with memory timing on the 845G chipset.

I have seen similar reports on Abit BG7, GigaByte 8IGX and Epox 845G threads. The 845G chip is a dog - STAY AWAY!!!