Ramm issue

Hello everyone.
Here's the thing. I have a Dell Optiplex 745 modified system. Among other things I have replaced RAM module with Patriot 4 GB (2+2 Kit). Recently I tested the memory modules with Memtest86 and it came back just fine with no errors. But I've noticed one thing. Memtest reported clock speed at 233 MHz (DDR532) with CAS 1-1-1-31. Processor FSB is also 233 MHz (don't know if it matters).

Now through BIOS i see that the memory modules are at 800 MHz Dual Channel Interleaved. Also CPU-Z reports 400 MHz speed. I understand that in Dual Channel memory types the clock speed is reported as half of the manufacturer report, but the Memtest86 bugs me. 233 MHz is not half.

So, is everything normal or do I need to take care of something?

SYS spec: mbo-intel q9645; cpu-intel core 2 duo 6400 2,13 MHz; ram-patriot 4 GB (2+2 Kit) 800 MHz; psu-ocz extreme 650w.
Also, the BIOS is copletely useless because I'm not allowed to change anything throgh it. Dell made it impossible. And all the drivers, including BIOS are up to date.

Thx

Welcome to Tom's Forum!

Look at the 'Memory' tab in CPU-z then multiply 'DRAM Frequency' * 2 -- that's the speed that the RAM running. I'm assuming it's running at DDR2-533.

Memtest is primarily designed to test your memory sticks, so I wouldn't expect it to be very accurate with RAM speed and timings.

Just go by what CPU-Z shows you. You can also check this in the BIOS.

In short, everything's fine.

Go in bios and make sure your DRAM frequency is set to 400mhz. Also check your timings and voltages are set correctly according to the sticker on the dimms. Auto does not always work properly.

Wow. Enough info to process. Long story short. I cannot cahange anything in the BIOS, CPU-Z tab "memory" is grayed out so I can't get any info from there - I don't know why, and I'm still a little confused... Do the ram modules run at 800 MHz or not? And if they do not, is there a way to fix this?

The RAM is capable of running DDR2-800, but not on your system. Everyone gets 'goo goo eyes' with Frequency but they for some reason ignore CAS; again see the chart. 'Typically' it's the 2nd pair of DIMM slots further from the CPU, and I stated some MOBO's aren't fully supported with CPU-z. All that matters is Memtest.

Analogy:
You have to look at RAM as a whole Frequency {bandwidth} and CAS {pauses} with transmission. Think of it this way a car can instantly go 100 MPH but the Stops are longer (9 sec) vs 75 MPH but the stops are shorter (7 sec) both with a 100 stops in a mile. Further, the CPU however says you can run only 85 MPH.

How long does the car take to drive a mile?

You are at factory speed right now.

If you look at your 'CPU' tab, note the Bus Speed that's what you want your RAM to run at e.g. 266MHz * 2 = DDR2-533 <or> 1:1. Your BIOS probably lacks FSB and CPU Ratio settings.

Again, DDR2-533 CAS 1 vs DDR2-800 CAS 3 is basically the SAME speed. If your PC seems slow then it's not because of the RAM -- it's the CPU, HDD, GPU, etc.

You might want to take a minute and review what I posted again. Particularly the graph Frequency vs CAS.

The RAM Frequency will run twice the FSB speed (1:1), BUT at a higher CAS. AGAIN, the 'speed' of RAM is a FUNCTION of BOTH Frequency and CAS. The overall speed translated to performance might increase 0% to 2%. By raising the FSB you would also be overclocking the CPU.

You need to expand your knowledge to know RAM's performance is bound to: CPU's IMC (or Memory Chip Controller (MCC)), RAM Frequency and RAM CAS Timings. Both the RAM's Frequency and CAS are EQUALLY important.

Helpful thread -> http://www.tomshardware.com/forum/ [...] erclocking

RAM: DDR2-533 CAS 1 vs DDR2-800 CAS 3 is more less the same 'performance'. Folks assume incorrectly RAM is all about Frequency and e.g. 533 vs 800 is 33% increase it is NOT!!!!

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Here's an example of DDR3-1333 vs DDR3-2133 -> http://www.bit-tech.net/hardware/m [...] y-bridge/4

There are similar DDR2 comparisons, just Google.