Cool n Quiet changes Ram speed too?

[Ecliptic]

I just built a htpc using an AMD BE-2300. I have enabled cool n quiet for the first time ever in my systems. I know that this feature throttles down the cpu but didnt know it throttles down the ram also. Is there any way to keep the ram speed constant? I am using ddr2 6400 set at at 800ddr (380mhz actual due to 5 multiplier 1900/5) and when the cpu throttles down to 1ghz, the rams speed drops to 200mhz (1000/5). I would figure the ratio would dynamically change to keep the ram speed constant.

 

[myocardia]

Why would you need 800 Mhz RAM, when your CPU is only running @ 1,000 Mhz?

 

[Ecliptic]

well, aren't some applications more memory intensive than cpu intensive? In addition, now that a lot of A/V processing is offloaded from the CPU to the graphics processor, couldnt there be cases where the computer is active processing A/V and need memory bandwidth but the cpu remains throttled down to 1Ghz? In such cases wouldn't I want full memory bandwidth?

 

[VirtualLarry]

Originally posted by: Ecliptic
well, aren't some applications more memory intensive than cpu intensive? In addition, now that a lot of A/V processing is offloaded from the CPU to the graphics processor, couldnt there be cases where the computer is active processing A/V and need memory bandwidth but the cpu remains throttled down to 1Ghz? In such cases wouldn't I want full memory bandwidth?

That's a very good point. I wasn't aware that CnQ throttled down the RAM speed, however. The RAM speed is based on a divisor off of the FSB speed, and the CPU speed is based on a multiplier off of the FSB speed. The FSB speed doesn't change with CnQ, only the CPU multiplier and the voltage, IIRC. So there shouldn't be any reason why the RAM speed changes, as far as I can see.

How are you measuring this?

 

[taltamir]

yea some applications are ram intesive... but if you are running such an intesive application why in the blazes will your cpu be throttled down? if it is then there is a serious flaw in CnQ.

Anyways if the multiplier change is affecting ram it is actually making it FASTER. It does drop to 200 mhz, it RISES to 200mhz.... and DRR2 mean you multiply that number by 4, but no reporting tool actually sees that... giving you total speed of 800mhz when it is throttled. When it is not throttled you are at around 750mhz real speed due to the odd multiplier.

 

[Ecliptic]

I am taking the reading from cpu-z.

at full cpu speed, cpu-z list memory as:
DRAM Frequency: 380Mhz
FSB: DRAM: CPU/5


at throttled to 1Ghz CPU:
DRAM Frequency: 200Mhz
FSB: DRAM: CPU/5

it looks like memory is a divider of CPU speed, not FSB. Or at least that is what CPU-z is leading me to believe. So when cpu changes speed, it affects memory. Is this normal and is there any way to lock the memory speed at max?

 

[Ecliptic]

Originally posted by: taltamir
yea some applications are ram intesive... but if you are running such an intesive application why in the blazes will your cpu be throttled down? if it is then there is a serious flaw in CnQ.

Anyways if the multiplier change is affecting ram it is actually making it FASTER. It does drop to 200 mhz, it RISES to 200mhz.... and DRR2 mean you multiply that number by 4, but no reporting tool actually sees that... giving you total speed of 800mhz when it is throttled. When it is not throttled you are at around 750mhz real speed due to the odd multiplier.

DDR is double data rate, so you multiply by 2 not 4. 380mhz = 760ddr, 200mhz = 400ddr

 

[DrMrLordX]

Brisbane CPUs will adjust RAM speed downward in conjunction with CPU multi. The way this is handles seems to vary based on the stock multiplier; for example, the 65nm X2-3600+ (stock multiplier of 9.5) will run your memory at (CPU multi)* 10% unless you're using the 1:1 memory ratio (then certain CPU multipliers will use full memory speed, while others will still use the above formula).

So far as I can tell, this is some kind of power-saving feature associated with CnQ. As it downclocks your processor, it also downclocks your memory. The only solution I can see to this is either to disable CnQ or to use the 1:1 ratio.

 

[taltamir]

Originally posted by: Ecliptic

Originally posted by: taltamir
yea some applications are ram intesive... but if you are running such an intesive application why in the blazes will your cpu be throttled down? if it is then there is a serious flaw in CnQ.

Anyways if the multiplier change is affecting ram it is actually making it FASTER. It does drop to 200 mhz, it RISES to 200mhz.... and DRR2 mean you multiply that number by 4, but no reporting tool actually sees that... giving you total speed of 800mhz when it is throttled. When it is not throttled you are at around 750mhz real speed due to the odd multiplier.

DDR is double data rate, so you multiply by 2 not 4. 380mhz = 760ddr, 200mhz = 400ddr

look again, I clearly said ddr2... also the rig mentioned works with DDR2... so it is multiplied by 4.

 

[kotrtim]

Originally posted by: DrMrLordX
Brisbane CPUs will adjust RAM speed downward in conjunction with CPU multi.

brisbane, windsor and turions all reduce their RAM speed together with he CPU, so its normal.
I think memory intensive application will normally be CPU intensive, or its CPU usage is high enough to trigger the CPU to increase its speed to maximum.

 

[Comdrpopnfresh]

I know that with my 939 system, cpu-z gets the ramrocessor dividers screwy and reports my ram running below 2x fsb speeds. Just isn't true. If you think cpu-z (if that is what you are using) is giving you erratic readings, use ntune, or something else. I don't know about am2, but everyone above seems to be in agreement it does scale.

 

[The-Noid]

Originally posted by: taltamir

Originally posted by: Ecliptic

Originally posted by: taltamir
yea some applications are ram intesive... but if you are running such an intesive application why in the blazes will your cpu be throttled down? if it is then there is a serious flaw in CnQ.

Anyways if the multiplier change is affecting ram it is actually making it FASTER. It does drop to 200 mhz, it RISES to 200mhz.... and DRR2 mean you multiply that number by 4, but no reporting tool actually sees that... giving you total speed of 800mhz when it is throttled. When it is not throttled you are at around 750mhz real speed due to the odd multiplier.

DDR is double data rate, so you multiply by 2 not 4. 380mhz = 760ddr, 200mhz = 400ddr

look again, I clearly said ddr2... also the rig mentioned works with DDR2... so it is multiplied by 4.

Incorrect. 200 mhz cpu == 400 mhz ddr2.