Bad memory latency

[Espen]

Hi

My computer acting slow and have than that for a long time. My CPU works very much and get up to 100% when playing HD movies for example. Even playing online poker can get the cpu working hard! Have searched the web for answears and tried lots of things, but nothing good so far. My computer is P4 3GHZ, 1536mb ram, 620GB HD, Geforce 6600GT.

I tried Everest Home Edition today. On the Benchmark, my computer got very bad on memory read; 1608mb/s and very bad at memory latency I suppose; 287,4ns.

Im not realy know exactly what these results means, but I looked at the web and it seems my computers memory is very slow. Do any one know what can cause this? And how to get normal memory speed again?

[Nelson37]

Describe number and type of RAM chips. You either have 3x512 or 1x512 and 1x1024. Either way no DDR, possible mismatch issue.

Several things to try. Check BIOS and make sure bus speeds are set properly. Also reduce to only one stick of RAM and test that, this is to eliminate any compatibility issues. Do this with each stick.

[jagabo]

Memory latency probably isn't your problem.

There are a few other possibilities though:

Make sure you drives are running in DMA mode. Dropping down to PIO mode slows the computer down quite a lot.

Make sure your graphics card has video overlay enabled. Without video overlay the CPU has to do all the scaling and colorspace conversion when putting video on the screen.

Bring up Task Manager (alt+ctrl+del) and switch to the Processes tab. See which processes are eating your CPU cycles (the CPU column) when your system is bogged down.

[Espen]

I have dma set for all my Harddrives. Im pretty sure graphic is in overlay, its set as default. Didnt find the settings in nvidias settings. Whats take cpu dempends on what I do. If I surf its firefox, burning dvds its nero, Looking at HD videos its the media player.

Why shouldnt the memory be a problem? I looked for memory latency at the web and my latency is as bad as on a P2 266MHZ!! A computer at my spec should have maybe 60-70ns. I dont realy know what it means, but it sure cant be good! Right?

As I wrot earlier, my memory read speed is also bad; 1608mb/s. Can this be a problem?

[jagabo]

Make sure your L1 and L2 caches are enabled in the BIOS.

[Krispy Kritter]

As noted above, verify the type, number, and size of the memory sticks you are using. If you are currently using a 1gb and a 512MB combo, try removing the 512MB (and vice versa) stick and retest. This will help identify which stick is slow. If all of the sticks test slow, then you have a BIOS config issue or just slow memory.

*NOTE: cpu speed has nothing to do with memory benchmarks. It is possible to get MB's which support new cpu's but use older memory. Older style memory will be slower.

[oldandinthe way]

Your memory performance can also be a function of they size memory modules you have in your system. If you have uneven sizes of Dimms you can get less than optimal performance. For instance you had 2 256mb DIMMS in the system and added a 512mb Dimm to get to 1gb. Your memory performance will be more than with only the two original DIMMs.

On many mobos the 1gb and 512mb combo Krispy Kritter describes will perform more slowly than either the 1gb or 512mb alone.

Read the manual for you mobo. It will tell you if it is one of those systems.