CPU FSB/Memory Speeds

ScottMcAnally

Junior Member
Jan 17, 2008
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Just bought a motherboard/processor/memory upgrade and I've been running into a few problems. Set everything up, turned on great. Looked in the BIOS and everything seemed to be running at full speed. I adjusted the memory timings and voltages to the manufacturers recommendations. Booted up and started CPUz. Told me my processor was running at a MUCH LOWER FSB and that my memory was running at half its speed.

Here's the hardware I'm having trouble with:

MSI P6N SLI Platinum Link

Intel Core 2 Duo E6750 Link

Patriot Extreme Performance 2GB Link

This is what my BIOS are telling me.

As you can see, it states that my processor is running at 1333 MHz and giving me a good 2.681 GHz. This is what I paid for.

Memory is running at 800 MHz as well. Notice my memory timings and voltage as well.

Now check out CPUz. Things don't look correct on the memory pages as well. Memory module one. Memory module three.

This is really what got me worried. If MSI's own software is saying it is underclocked, then something is going on here.

This is VERY confusing and I have noticed that my computer seems to be running slower than before the upgrade. This should not be since I'm coming from a AMD Athlon 64 3500+.

Any help would be greatly appreciated. Thank you for reading.
 

cozumel

Senior member
Nov 29, 2007
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You CPU slows down (and voltage should drop) when it is not being used in accordance EIST/C1E specification. If you run some applications, a game, PI or prime95 and keep CPU-Z open you'll see the processor speed moving up. Memory is running at DDR2 400x2=800MHz.

The mobo you have chosen won't get the full performance out of your rig. The 650i chipset, while ok is out-performed by 680/780/P35 and X38 chipsets but you should still notice a considerable improvement over your rpevious AMD-based rig.
 

ScottMcAnally

Junior Member
Jan 17, 2008
9
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0
Thanks for the response.

I guess I'm a little confused. I am not experiencing a slow down in CPU speed, just the FSB. Is this what you mean? From what I know, energy efficiency programs usually drop the frequency, not the FSB.

Also, if I'm running my memory in dual channel, does that really mean I can only get 400 MHz from each? Thanks.
 

ScottMcAnally

Junior Member
Jan 17, 2008
9
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I was just ripping a CD, a task which used to be easily done by my computer, and it nearly brought my computer to a stand still while importing. What would be causing this?
 

cozumel

Senior member
Nov 29, 2007
337
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Originally posted by: ScottMcAnally
Thanks for the response.

I guess I'm a little confused. I am not experiencing a slow down in CPU speed, just the FSB. Is this what you mean? From what I know, energy efficiency programs usually drop the frequency, not the FSB.

Also, if I'm running my memory in dual channel, does that really mean I can only get 400 MHz from each? Thanks.

If I remember right your CPU is rated at 333.3x8. CPU-Z correctly reports that your CPU is running at 333.3x6=2000MHz.

The memory is double data ram which means it transfers data twice in every clock cycle so 400MHZ=DDR2 800 and 533MHz=DDR2 1066MHz etc.

As far as your general perfomance goes, you will need to make a new thread within the 'Computer Help' forum to ensure a good response. You will also need to post your entire system configuratiuon and specification including OS, hdds, opticals, PSU etc etc stating the exact problem and symptoms.
 

ScottMcAnally

Junior Member
Jan 17, 2008
9
0
0
Alright, so according to CPUz, my processor is actually running at it's full 1333 MHz?

I know this may be a little off topic, but I'm curious as to what the FSB is? I've looked it up but am perplexed by various explanations, maybe someone can explain it in layman's terms for me?

I think I understand that the FSB times the multiplier equals the frequency of your CPU, but what is the purpose of the FSB? And why is it that at online stores the FSB is rated as "1333 MHz" when it is called something else in CPUz. Thank you!
 

Idontcare

Elite Member
Oct 10, 1999
21,110
59
91
The system bus speed determines how fast or slow everything else will run as everything else if running a clock-multiplier of the system bus.

So a system Bus speed of 333.33 MHz means your FSB is 1333 MHz because the FSB is "QDR" or quad-data-rate which means 4X multiplier.

Change your bus speed to 266.67 and your FSB, which is still QDR or multiplier of 4X, becomes 1066 MHz. Change your bus to 400 MHz and your FSB becomes 1600 MHz (4x still).

What about ram? Ram typically runs as 2X the bus (this is called 1:1 ratio). So a 333MHz bus will usually mean your ram is running at DDR-667 "667MHz" speeds. Increase the bus to 400 MHz and your 1:1 ram is now running at 2X the bus or DDR-800.

(The caveat here is some people run with an additional clock multiplier increase on their ram. So the Bus maybe at 333Mhz, and 1:1 ratio ram would be 2X that or DDR2-667, but folks might still clock their ram to DDR2-800 with a ram multiplier of 5:6 in the BIOS)

Now you CPU runs a clock multiple off the bus as well. Depends on the CPU as to what your clock multipier is, as well as the CPU's intended stock bus speed. a Q6600 has a stock multiplier of 9X and is intended to run a stock bus speed of 266.67 MHz. 9x267 = 2400MHz or 2.4 GHz.

But EIST/C1E will reduce the CPU clock multiplier on the fly to 6X in order to conserve power when idle.