A8N-SLi Premium 4 x 512Mb Dual Channel running @ 333Mhz instead of 400Mhz

Hi

Ive been using 2 x 512Mb PC3200 which is auto detected to run in Dual
Channel DDR 400Mhz.

Ive just fitted another 2 x 512Mb PC3200.

At boot up it shows 2Gb but now it says Dual Channel @ 333Mhz.

The mobo is an ASUS A8N-SLi Premium.

I have the BIOS set to auto detect.

Is it OK to manually adjust the RAM speed up to to 200Mhz so that it runs at
DDR 400?

I dont understand why it isnt automatically set to run at 400Mhz. Can
anyone explain why its gone down to 333Mhz?

As an aside... it took me an age inserting/removing/reinserting the RAM
before they were all recognised. It took over an hour! For a while I
thought I had killed my Mobo and/or some of the RAM. Cant believe it was so
iffy. I can only think that it may have been dust in the empty slots which
caused the problem! Has anyone else had that sort of problem?

Thanks for any info

Ian

Ian R wrote:

> Is it OK to manually adjust the RAM speed up to to 200Mhz so that it runs at
> DDR 400?
>
> I dont understand why it isnt automatically set to run at 400Mhz. Can
> anyone explain why its gone down to 333Mhz?

Hi Ian -

I have the same Mb. I believe the reason the board slows the RAM when
are four slots are populated has to do with stability and/or memory
controller issues. To the best of my knowledge, there are no safety
issues involved. You can set the clock rate manually in your BIOS and
run your programs to see if everything is stable. If unstable, make
sure your timings are relaxed to 2T. If you still have problems, then
back to 333Mhz you go.

I have the Thermaltake Pure Power 600w what on my P5W DH SLIi/CROSSFIRE MB,
increased my boot speed over my Enermax 460w.,$104.99 and free shipping at
newegg.com. Best power supply I've ever had.


"Ian R" <> wrote in message
news:...
> Hi
>
> Ive been using 2 x 512Mb PC3200 which is auto detected to run in Dual
> Channel DDR 400Mhz.
>
> Ive just fitted another 2 x 512Mb PC3200.
>
> At boot up it shows 2Gb but now it says Dual Channel @ 333Mhz.
>
> The mobo is an ASUS A8N-SLi Premium.
>
> I have the BIOS set to auto detect.
>
> Is it OK to manually adjust the RAM speed up to to 200Mhz so that it runs
> at DDR 400?
>
> I dont understand why it isnt automatically set to run at 400Mhz. Can
> anyone explain why its gone down to 333Mhz?
>
> As an aside... it took me an age inserting/removing/reinserting the RAM
> before they were all recognised. It took over an hour! For a while I
> thought I had killed my Mobo and/or some of the RAM. Cant believe it was
> so iffy. I can only think that it may have been dust in the empty slots
> which caused the problem! Has anyone else had that sort of problem?
>
> Thanks for any info
>
> Ian
>
>
>
>

SumGuy wrote:
> Ian R wrote:
>
>> Is it OK to manually adjust the RAM speed up to to 200Mhz so that it
>> runs at DDR 400?
>>
>> I dont understand why it isnt automatically set to run at 400Mhz. Can
>> anyone explain why its gone down to 333Mhz?
>
> Hi Ian -
>
> I have the same Mb. I believe the reason the board slows the RAM when
> are four slots are populated has to do with stability and/or memory
> controller issues. To the best of my knowledge, there are no safety
> issues involved. You can set the clock rate manually in your BIOS and
> run your programs to see if everything is stable. If unstable, make
> sure your timings are relaxed to 2T. If you still have problems, then
> back to 333Mhz you go.

And by "timings are relaxed to 2T", SumGuy is referring to the
Command Rate setting in the BIOS.

Paul

"SumGuy" <> wrote in message
news:PB5Ch.3461$lo1.168@trndny05
> Ian R wrote:
>
>> Is it OK to manually adjust the RAM speed up to to 200Mhz so that it
>> runs at DDR 400?
>>
>> I dont understand why it isnt automatically set to run at 400Mhz. Can
>> anyone explain why its gone down to 333Mhz?
>
> I have the same Mb. I believe the reason the board slows the RAM when
> are four slots are populated has to do with stability and/or memory
> controller issues.

ASUS do it because it's in the AMD spec. However, Rev E CPUs have much
better memory controllers than the old steppings and it's rarely if ever an
issue, at least at stock speeds.

Paul wrote:

> And by "timings are relaxed to 2T", SumGuy is referring to the
> Command Rate setting in the BIOS.
>
> Paul

Thanks, Paul. I should not have left that part out !!

-Scott

"Ian R" <> wrote in message
news:...
> Hi
>
> Ive been using 2 x 512Mb PC3200 which is auto detected to run in Dual
> Channel DDR 400Mhz.
>
> Ive just fitted another 2 x 512Mb PC3200.
>
> At boot up it shows 2Gb but now it says Dual Channel @ 333Mhz.
>
> The mobo is an ASUS A8N-SLi Premium.
>
> I have the BIOS set to auto detect.
>
> Is it OK to manually adjust the RAM speed up to to 200Mhz so that it runs
> at DDR 400?
>
> I dont understand why it isnt automatically set to run at 400Mhz. Can
> anyone explain why its gone down to 333Mhz?
>
> As an aside... it took me an age inserting/removing/reinserting the RAM
> before they were all recognised. It took over an hour! For a while I
> thought I had killed my Mobo and/or some of the RAM. Cant believe it was
> so iffy. I can only think that it may have been dust in the empty slots
> which caused the problem! Has anyone else had that sort of problem?
>
> Thanks for any info
>
> Ian
>

Hi Guys

Thanks to all of you for replying.

I manually set the memory to 400Mhz.

I then ran a memtest utility for a few hours which ran the CPU and memory @
100% and to my relief and pleasure it showed no errors - Phew!

Ian I^)