Noob Overclocking Question

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htpc_user

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I normally don't overclock but I'm giving a friend an old PC of mine and was going to overclock it a little. What I'm wondering is should the power saving stuff like Cool & Quiet or Speedstep be disabled? Or will they still do their job and then kick in the overclock when needed? I notice that when enabled and you go to System it shows the CPU and its rated stock speed. But if it's disabled and you go to System in Windows then it shows the CPU and the overclocked speed.
 
depends on how old the system is and what type of overclocking you are doing. if its am2 or older and multiplier overclocking then turn it off, if its FSB(ht reference clock) then you can leave it on.
 
It really depends on the processor model, what type of C-State the platform supports(C1, C1E, C2E) and the and the type (software/BIOS) and amount of overclock. Some C-States change the multiplier, some reduce Vcore.
When I had a dual core Opteron 165 1.8Ghz, if I pushed it to its max around 2.8Ghz, when the AMD Cool 'N' Quiet kick in it would sometimes cause instability, and I remember hearing some claim that some games would have a slight micro stutter when the processor multiplier speed changed. With my Intel overclocking, C1E would reduce the voltage also, so if you needed a certain voltage bump to reach a certain clock speed, reducing it could cause instability. On my current system, I leave it OC'd at 3.6Ghz daily.
With software overclocking that comes with your motherboard (like MSI's OC Gennie or Asus smart dr.), there is sometimes a preset 10% or 20% mild overclock, and this should work fine with power saving BIOS settings because the software can increase the voltage for you, and sometimes dynamically.
In regards to seeing the OC speed, when you run Prime 95 to max out the cores or run a benchmark the speed will increase. Most-- if not all-- games wont come close to maxing out your cores like that.
 
I have another noob overclocking question.

I've overclocked a couple of my systems now, and one thing that I noticed is that when I overclock by FSB that it overclocks the memory too. So if I have DDR2 800 RAM then it goes up to 9xx-something. Now I see why memory plays a big part on the overclock of the cpu. This afternoon I upgraded my son's PC by putting 2 x 2gb of 1066 RAM and taking out his 2 x 1gb of 800. But when I booted up the motherboard it still had it set as 800 (my own ECS board did this when I upgraded and I had to manually set it instead of leaving it at automatic). But when I overclocked his system his RAM went up to 9xx-something, so it was still under its rating of 1066. So what I'm wondering is, could you purposefully set RAM under its rated speed and then when overclocked it would be under or near its rated speed? I'm not sure my question even makes sense, but I guess my line of thinking is that you wouldn't have to worry about the memory maxing out before the cpu does?
 
htpc_user said:
I have another noob overclocking question.

I've overclocked a couple of my systems now, and one thing that I noticed is that when I overclock by FSB that it overclocks the memory too. So if I have DDR2 800 RAM then it goes up to 9xx-something. Now I see why memory plays a big part on the overclock of the cpu. This afternoon I upgraded my son's PC by putting 2 x 2gb of 1066 RAM and taking out his 2 x 1gb of 800. But when I booted up the motherboard it still had it set as 800 (my own ECS board did this when I upgraded and I had to manually set it instead of leaving it at automatic). But when I overclocked his system his RAM went up to 9xx-something, so it was still under its rating of 1066. So what I'm wondering is, could you purposefully set RAM under its rated speed and then when overclocked it would be under or near its rated speed? I'm not sure my question even makes sense, but I guess my line of thinking is that you wouldn't have to worry about the memory maxing out before the cpu does?
Click to expand...

Yes, thats exactly it!

for example,
My CPU is a Q9550 which is 333Mhz x 8.5 so if I had DDR800, the MB would automatically run a 5:6 divider to have the ram at 800MHz.
I have DDR1066 though, and I run my FSB at 425 and my multiplier is 8.5, so now running with the 5:6 divider my DDR1066 ram runs at 1020Mhz, so safely below 1066mhz .

here is a handy calculator to figure out memory divider needed for certain OCs:
http://www.guru3d.com/news/download-cpucalc-196/

If you have a locked multiplier like me on your CPU (8.5x), you have to OC by raising the FSB or CPU speed, but that raises the memory speed. That is why you use a memory divider in your bios settings to then lower the memory speed to something within range of its max. That is the art of the OC.

Your sons MB kept the old multiplier, which then worked out for your OC.

Download CPU-Z and you can see the multiplier, Bus speed, and your memory speed and divider being used. You can even read the SPD values of your ram modules, this is the part that tells your MB what speeds the RAM is rated to run at. Often, the MB does not read these and will not auto adjust, like in your case.
 
htpc_user said:
I have another noob overclocking question.

I've overclocked a couple of my systems now, and one thing that I noticed is that when I overclock by FSB that it overclocks the memory too. So if I have DDR2 800 RAM then it goes up to 9xx-something. Now I see why memory plays a big part on the overclock of the cpu. This afternoon I upgraded my son's PC by putting 2 x 2gb of 1066 RAM and taking out his 2 x 1gb of 800. But when I booted up the motherboard it still had it set as 800 (my own ECS board did this when I upgraded and I had to manually set it instead of leaving it at automatic). But when I overclocked his system his RAM went up to 9xx-something, so it was still under its rating of 1066. So what I'm wondering is, could you purposefully set RAM under its rated speed and then when overclocked it would be under or near its rated speed? I'm not sure my question even makes sense, but I guess my line of thinking is that you wouldn't have to worry about the memory maxing out before the cpu does?
Click to expand...

Some of the "newer" S775 MBs will allow independant control of the memory speeds as well.
Well actually, you set a memory "strap" and the memory controller will find the closest divider to give you your desired memory speed based on the FSB. So yes, depending on your BIOS you can lock in the memory more or less where you want it and just adjust the cpu. Recall that 1066 memory is just overclocked 800 memory.

I like to OC by independantly adjusting the cpu and the memory. That way you only deal with one variable at a time.
If you dont put some limits on the memory, the system will automatically take the memory up when you adjust the FSB.:D
 
Hmmmm, I did a little researching, and I think I am getting a little better understanding. I'm still a little confused though. I am overclocking an E2180. Just doing a mild overclock to 2.4 using a 240 FSB. I have OCZ PC2-6400 RAM. I went into the BIOS and changed the speed of the memory to DDR-722 (it had some weird choices, but I'm guessing this is for overclocking purposes). So in this overclocking example, what would the memory be running at after the overclock?
 
htpc_user said:
I normally don't overclock but I'm giving a friend an old PC of mine and was going to overclock it a little. What I'm wondering is should the power saving stuff like Cool & Quiet or Speedstep be disabled? Or will they still do their job and then kick in the overclock when needed? I notice that when enabled and you go to System it shows the CPU and its rated stock speed. But if it's disabled and you go to System in Windows then it shows the CPU and the overclocked speed.
Click to expand...


Leave it on. It will enable the processor to run cooler, burn far less energy when idle, and it will also extend the life a little more of a CPU that is already being shortened by overclocking.

That last part doesnt matter because I have read that CPU's even heavily overclocked might go from lasting 100 years to 95 years from overclocking haha. Not a big deal.
 
Can someone explain the formula to me for figuring what the speed of the RAM ends up being after overclock based on the FSB setting and what the RAM is set to?

E2180 with FSB set to 240 and RAM set to DDR2 722. How would I figure the speed it ends up running at?
 
Most motherboards list the dividers as ratios, 1:2, 3:5, 5:8, 2:3, 3:4, 4:5, 5:6, 1:1, Some MBs list it like 266, 333, 400, 533 etc.

DDR800 runs at I/O bus clock of 400 and its data rate is 800 (DDR2-800)

Stock at 200mhz CPU FSB, if you use a the 1:2 or 400 divider your ram I/O bus clock is 400 so since it is double data rate (DDR2) it is running at DDR800. A divider of 3:4 would be for DDR1066 ram. (200 to 266 is 3:4 ratio)

If you dont change the RAM divider and increase the FSB to 240, then using the 1:2 or 400 divider your RAM is 480 or DDR960. (240:480 is 1:2) with the 3:5 divider or 333 divider it is DDR800.

So if you are using the 3:5 or 333 divider, divide your FSB by 3 and then multiply the result by 5 and you get 400 ( I/O bus clock ) and 800 data rate.

Or you could use the calculator I linked to that has you processor in the Choose your CPU selection:
http://www.guru3d.com/news/download-cpucalc-196/

:)
 
semiconductorslave said:
Most motherboards list the dividers as ratios, 1:2, 3:5, 5:8, 2:3, 3:4, 4:5, 5:6, 1:1, Some MBs list it like 266, 333, 400, 533 etc.

DDR800 runs at I/O bus clock of 400 and its data rate is 800 (DDR2-800)

Stock at 200mhz CPU FSB, if you use a the 1:2 or 400 divider your ram I/O bus clock is 400 so since it is double data rate (DDR2) it is running at DDR800. A divider of 3:4 would be for DDR1066 ram. (200 to 266 is 3:4 ratio)

If you dont change the RAM divider and increase the FSB to 240, then using the 1:2 or 400 divider your RAM is 480 or DDR960. (240:480 is 1:2) with the 3:5 divider or 333 divider it is DDR800.

So if you are using the 3:5 or 333 divider, divide your FSB by 3 and then multiply the result by 5 and you get 400 ( I/O bus clock ) and 800 data rate.

Or you could use the calculator I linked to that has you processor in the Choose your CPU selection:
http://www.guru3d.com/news/download-cpucalc-196/

:)
Click to expand...

Thanks. That's a little easier to figure. I tried the calculator but I couldn't really make anything of it. I understand your calculation but there is 1 thing strange to me. My motherboard gives me choices of the RAM speed, and I chose the DDR2 722 option. CPU-Z shows me the divider is 2:3. So by your calculation that's 240/2=120 * 3 = 360, so that would mean a 720 data rate. Which is right at the speed it's listed as, 722. So choosing 800=960, but choosing 722=720? Or is the motherboard giving this rated speed because of the FSB being set at 240?

Edit: Ahhhh, I think I see. I was under the impression that because I am overclocking the CPU that the RAM was being overclocked from its setting as well, just like on my son's system. But when I specify the RAM speed in the BIOS, that is what the RAM is running at regardless of what the FSB is set to. When I choose DDR2 800, cpu-z shows a 3:5 divider. Evidently on this ASUS board you just tell it what to run at and it adjusts to get that spec. I was confused because my son's Gigabyte when setting the RAM to DDR2 800 and overclocked with an FSB of 239 was also overclocking the RAM to 940 or something like that. Or it could be because I am setting the RAM to 800 manually on the ASUS board, and I may have it set to Auto on his Gigabyte (not sure).

One other thing...when looking at CPU-Z under Core Speed and Multiplier it jumps back and forth between 2400 MHz/x10.0 to 1439.5/x6.0. Why does it show it like that? I have SpeedStep turned off in the BIOS and Windows set to "High Performance". Is there something else that's causing that? Should I even be worried about that?
 
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htpc_user said:
One other thing...when looking at CPU-Z under Core Speed and Multiplier it jumps back and forth between 2400 MHz/x10.0 to 1439.5/x6.0. Why does it show it like that? I have SpeedStep turned off in the BIOS and Windows set to "High Performance". Is there something else that's causing that? Should I even be worried about that?
Click to expand...

There is speedstep EIST (Enhanced Intel Speedstep Technology) but often also CxE state(ie. C1E, C2E) options in the BIOS that can reduce voltage and multiplier, something has to be enabled if you see the multiplier changeing dyanmicaly.

My EVGA 780 MB had a setting where you could type in a memory speed, and it would always adjust the RAM divider to try and match. My current Gigabyte board you have to anticipate what your OC will do to your ram, and then set the correct divider (though it irks me cause they dont display the ratios, they have a weird naming scheeme like 400A, 400B, 400C etc.)

If you have DDR 800 and your running it at 720, that means you could increase your CPU OC before you run into a wall cause of your RAM. But since your giving it to a friend, you might not want to OC too high, or you'll be the one going over to fix it when it starts overheating or blue screening due to a little dust and cat hair over the CPU cooler fins :) If you clock it lower it will be more tolerant to abuse.
 
tangoseal said:
Leave it on. It will enable the processor to run cooler, burn far less energy when idle, and it will also extend the life a little more of a CPU that is already being shortened by overclocking.

That last part doesnt matter because I have read that CPU's even heavily overclocked might go from lasting 100 years to 95 years from overclocking haha. Not a big deal.
Click to expand...

This isnt always true... when you know what you are doing with OC, and can fine tune properly, and maintain proper temps, an OC'd chip can last just as long as a non OCd chip... what kills it faster is the extra heat the added voltage will bring... most beginers when overclocking think that instability has to do with low votage so they crank it up when it could be many other factors when OCing...

In 2006 I built a gaming machine using the budget E6300 C2D (Factory speed of 1.86ghz)... I paired it with a Gigabyte DS3 Mobo, and Patriot Extreme DDR2-800 memory. I overclocked that chip to 3.42ghz... thats an amazing 83.9% Overclock and is almost unheard of today... i used that PC without throttling enabled and overclocked every day of its life until 2009 when I sold the PC to my brother in law... my Brother in law is STILL using that PC today and to my surprise, the machine is still running strong.

E6300 1,86ghz @ 3.42ghz for 6 years @ 183% clock speed....

Moral of my story? Overclocking will not kill your processor any faster than the advancement of technology will...
 
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