Doubled RAM, decreased performance!?

  • Thread starter Thread starter julyderek
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julyderek

Hi,

I have a P4 2.4Ghz overclocked to 2.7Ghz with 2 modules of 256MB DDR400
RAM on a ASUS P4S8x-x motherboard. I have a NVIDIA 6600GT 128MB AGP
Video card.

When I installed a futher module of 512MB DDR400 RAM the performance of
my PC has decreased....keeping everything else the same. I have
installed the 512MB in the 1st DIMM socket.

Checking the FPS on the games I play. The FPS has reduced by 10FPS
instead of increasing with the additional RAM!

Please help! Dunno what I am doing wrong?

Thanks in advance.

Derek
 
Hi,

I have a P4 2.4Ghz overclocked to 2.7Ghz with 2 modules of 256MB DDR400
RAM on a ASUS P4S8x-x motherboard. I have a NVIDIA 6600GT 128MB AGP
Video card.

When I installed a futher module of 512MB DDR400 RAM the performance of
my PC has decreased....keeping everything else the same. I have
installed the 512MB in the 1st DIMM socket.

Checking the FPS on the games I play. The FPS has reduced by 10FPS
instead of increasing with the additional RAM!

Please help! Dunno what I am doing wrong?

Thanks in advance.

Derek
Click to expand...

Elementary, My Dear Watson! The board is of a dual channel RAM
variety. By inserting "a futher module of 512MB DDR400 RAM" you
forced it into single channel mode, thus cutting memory bandwidth in
half, and p4 is *very* sensitive to memory bandwidth, to say the
least. Next time you do memory upgrade on this board, make sure it is
in identical module pairs.
 
A good guess, but the P4S8X-X (SiS 648 chipset) seems to be for the older
single-channel P4s. It is limited to a 533 MHz FSB (front side bus), and it
has 3 DIMM slots.

http://usa.asus.com/prog/spec.asp?m=P4S8X-X&langs=09

Checking the FAQ for the board gives:

---------------------------------------------------------------------------------------------------------------------

Question

Does P4S8X-X support PC2700 (DDR333) memory?

Answer

Yes, P4S8X-X can support PC2700 memory. However, according to SiS
specification, PC2700 only support up to 2 DIMMs at max.

-----------------------------------------------------------------------------------------------------------------------

This suggests that the board might be happier with a pair of DIMMs rather
than three, particularly if it's overclocked.

I wonder if the board changes the memory settings when all three slots are
populated? I use an Asus A8V Deluxe board (Athlon64, socket 939). When all
four of its DIMM sockets are populated, it is supposed to switch the memory
ratio so that PC3200 (DDR400) RAM runs at PC2700 (DDR333) for stability. (I
haven't seen that, as I have never used more than one dual-channel pair in
the board.) The work around for that is to manually set the memory frequency
and timings in the BIOS, at the rsik of instability.

HTH.

Bob Knowlden

Address may be scrambled. Replace nkbob with bobkn.
 
Thanks guys!

I am using Windows XP. What should I do? Should I remove the 256MB
Module and keep only 2 modules (512+256)? In which DIMM slots should I
populate the modules?

I dont think my Motherboard supports dual-channel memory. Check
http://www.asus.com/prog/spec.asp?m=P4S8X-X&langs=01

Thanks again
Click to expand...

You might want to go the horses mouth next time, for details, it does not
specifically state its dual channel but I did find this little tidbit
found here.

http://www.sis.com/products/sis648_features.htm

High Performance DDR Memory Controller
- Delivering up to 2.7GB/s Bandwidth
- Supports Up to 2 un-buffer DIMM DDR333 and up to 3 un-buffer DIMM DDR266
- Support Un-buffered DDR DIMM and up to 1GB per DIMM
- Suspend-to-RAM(STR)

What this tells me is that with three dimms, it could very will cut the
speed down to 266, this could be the reason you are experiencing less
performance.

You mentioned its only 10fps, whats the big deal! Just lower some of your
eye-candy in the game and gain it back if its that important to you. To me
that would be a good trade off, the more memory you have the less wait
time you will encounter during map loads. That will also mean you will be
ready sooner, so you can get more kills at least that works with most
FPS'es out their. I have a lowly socket A board with old graphics card
but with lots of ram, I lots of time can get 2-4 kills in before most
people finish loading their maps.

Gnu_Raiz
 
Hi & Thanks for your detailed reply.

I removed the 256MB Module from the 3rd slot and my benchmarking went
up by 1000 pts in Aquamark 3.

I am now running with 768MB till I get a second memory module of 512MB.
 
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