RAM running slow?

[Leggie]

Hi all, new here,

I'm working on an old computer running Windows 2000. Here are the specifications:
Motherboard: MSI KM4M-V (latest BIOS)
CPU: AMD Athlon XP 1800+
RAM: 1 DIMM of Crucial DDR 1GB PC2700
Graphics: GeForce 6200

The system is slow, of course, but in particular I'm intrigued by the RAM. I ran SiSoft Sandra's memory benchmark and it indicated it was only running at about 500MB/s, which seems very slow to me. I get a similar reading in Memtest86+ (no errors found). This seems a long way of the (admittedly peak) transfer rate for PC2700 of 2700MB/s.

I've manually set the RAM speed in the BIOS to 166MHz and set the timings as well; only odd thing I can see is that CPU-Z gives the timings it's actually running at as 2.5-5-3-7 rather than 2.5-3-3-7. Any ideas why this is happening, and is this likely to be the problem? If not, what else could it be?

Thanks in advance for any ideas.

Leggie

[Dingo]

Hi,

I would imagine that th timings issue is to do with the fact that you are using a single dimm of memory as opposed to the "dual channel" mode the mobo is supposed to run in (ie) two sticks of ram as opposed to the one you are using so the mobo is running single channel.

Check your bios to make sure it is set to single as opposed to dual channel (which it should default to) and the timings are 1T and not 2T.

[Fraz]

Do mobos from that era even support dual channel memory? I don't remember my Athlon mobo of that era having a dual channel memory controller...

[Leggie]

Thanks for the replies. The motherboard doesn't support dual-channel memory, so that's not going to be the problem. Any other ideas? Does 500MB/s seem slow to you?

[Fraz]

Thanks for the replies. The motherboard doesn't support dual-channel memory, so that's not going to be the problem. Any other ideas? Does 500MB/s seem slow to you?

Yes, 500 MB/s does definitely seem slow to me. That is strange.

The only thing I can think of is that you have some crazy divider setting, but it seems unlikely. The CPU:FSB divider should be set to 1:1 on old athlons - they don't like having the memory running asynchronously to the CPU as far as I remember.

[Leggie]

Yes, 500 MB/s does definitely seem slow to me. That is strange.

The only thing I can think of is that you have some crazy divider setting, but it seems unlikely. The CPU:FSB divider should be set to 1:1 on old athlons - they don't like having the memory running asynchronously to the CPU as far as I remember.

Well, the FSB is 133Mhz (rated at 266Mhz) and the FSB : DRAM ration is FSB + 33Mhz, according to CPU-Z. This allows the RAM to run at its rated speed of 166Mhz. Are you saying this is likely to be a problem?

[Fraz]

Well, the FSB is 133Mhz (rated at 266Mhz) and the FSB : DRAM ration is FSB + 33Mhz, according to CPU-Z. This allows the RAM to run at its rated speed of 166Mhz. Are you saying this is likely to be a problem?

Could be... so the divider is set to 1:1.25 I take it? I remember when I had an Athlon of that era and I tried it, the computer wasn't even stable.

Try putting the divider to 1:1 (so essentially you'll be underclocking your RAM), and see what happens when you re-run your tests. Only a vague hope, but might be worth trying.

Here is an old thread from some forum or other that I managed to dig up, which roughly speaking confirms what I'm thinking:

http://www.abxzone.com/forums/f67/wh...ous-82254.html

Although in the final post, the user does claim to getting his system stable with asynchronous timings. I certainly never managed it back in the day when I had an Athlon XP, and I know others that also tried and failed.

[Leggie]

Could be... so the divider is set to 1:1.25 I take it? I remember when I had an Athlon of that era and I tried it, the computer wasn't even stable.

Try putting the divider to 1:1 (so essentially you'll be underclocking your RAM), and see what happens when you re-run your tests. Only a vague hope, but might be worth trying.

Here is an old thread from some forum or other that I managed to dig up, which roughly speaking confirms what I'm thinking:


Although in the final post, the user does claim to getting his system stable with asynchronous timings. I certainly never managed it back in the day when I had an Athlon XP, and I know others that also tried and failed.

Thanks, tried that, still no luck, down to about 450MB/s with the FSB : DRAM on 1:1. This is weird...

[Dingo]

Thanks for the replies. The motherboard doesn't support dual-channel memory, so that's not going to be the problem. Any other ideas? Does 500MB/s seem slow to you?

http://www.msicomputer.com/product/p...p?model=KM4M-V

According to MSI your mobo does support dual channel so you are running in single channel mode with one stick of ram. Try manually setting the timing at 2-3-3-6 and see what you get.

[Leggie]

According to MSI your mobo does support dual channel so you are running in single channel mode with one stick of ram. Try manually setting the timing at 2-3-3-6 and see what you get.

I can't see where it says that on the specifications - can you point it out to me? Thanks.

I've already tried manually setting the timings (see above) but they don't seem to be taking effect according to CPU-Z. Any ideas why?

[Fraz]

Any ideas why?

Not saving your bios settings before exiting is all I can think of...

[Leggie]

Not saving your bios settings before exiting is all I can think of...

No, I'm definitely saving them, when I go back into the BIOS the timings are as I set them. They just don't seem to be taking effect.

[Fraz]

As I understand it, this dual channel business shouldn't be relevant. The module on its own should have a peak bandwidth of 2700 MB/s. Having two modules with a dual-channel memory controller should take the peak theoretical bandwidth up to 5400 MB/s.

Now, peak theoretical and real world are two different things, but 500 MB/s is way too low. I'd expect about half the peak theoretical in reality, so about 1400 MB/s. You're getting about 1/3 of this, so there is definitely something funny going on. As to what, I don't know.

Maybe post some pictures of your bios settings screen.

[Leggie]

Maybe post some pictures of your bios settings screen.

Sorry for the delay. Here are the photos.









Any ideas welcome.