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OCing the CPU makes it perform worse?

T

topeira

Member
hi there.

i've been trying to ever-so-slightly OC my CPU and it got worse.

i have a Q6600 and in the bios i tried changing the cpu host frequency to 290 but im not sure to what i should set the system mem multiplyer. i have options like 2.44, 2.66, 3.0 etc. my friend recommended 2.5 but i do not have such an option. whatever i set it to i get lower score with 3Dmark.

am i doing something wrong?
 
You will want to set the memory multiplier to whichever one gives you a 1:1 ratio. You can check that on the memory tab in cpu-z. A G0 stepping should do 9x333mhz (2.997ghz) without voltage adjustment and a 1:1 ratio would have memory running at an effective 667mhz (333x2). Overclocked Core 2 Quads run better this way.
 
thanks, azemsiB. just the answer i needed 🙂

boochi, im not sure im getting it.
if i adjust the cpu mhz to 333 than i should try and set the memory multi to 2?

what should give me a 1:1 ratio? how do i calculate that?

in cpu-z memory tab it says my memory frequency is around 530mhz. does that matter? 😛
 
Ok since my first post wasn't helpful, and my 2nd post may not be clear. I'll give you the steps to help you overclock (although you should read guides online. They're very helpful)

1. Ensure that your processor is running at acceptable temperatures. If it is not overclocked and it reaches high temperatures that are not acceptable (or close to unacceptable) then do not overclock until you get better cooling, or only overclock on stock voltage.
2. If you have done the first step, the next thing to do to make things easier is manually lock the CPU voltage to the stock voltage.
3. Next, set the FSB:Memory/RAM ratio to 1:1. To achieve this and confirm it properly, go to CPU-Z after you do the setting. If your FSB is at "333 MHz", then your memory should ALSO be at 333 MHz or 666 MHz (depending on how things are supposed to be read. A 1:1 ratio implies that the memory should be 333 MHz, but DDR is double data rate, so you multiply it by two) This step will make it easy to find the CPU overclock without worrying about memory issues.
4. Manually set your RAM voltage to what it is supposed to be rated at.
5. Slowly raise your FSB little by little (5-10 increments) and see if it can boot into Windows completely. When it can no longer do this, it's time to raise the voltage or lower the FSB speed. You can also accompany the "boot up test" with a short stress test to see if it's remotely stable before pushing things further.
6. Do this until the voltage requirements become too high (past the acceptable voltage. For Core 2 Quads on 45nm, I believe it is 1.4, and for 65nm, I believe it is 1.5V) or if the temperatures in stress testing become too high for your cooling.
7. After this, you can choose to optimize your memory by having it run at higher speeds or messing with the timings. I normally just follow the CPU-Z tab that tells you the lowest timings at certain speeds at certain voltages.
 
Q6600 has a stock fsb of 266. The ratio you want is determined by the speed of your ram. If you have "800mhz" ram (PC2-6400) then you're supposed to set your ram ratio to 800/266, which is 3:1. These are stock numbers.

Now when you overclock, you are increasing fsb from 266 to 333 (from 2.4 to 3.0 GHz). So if you keep that same memory ratio, your memory is now running at 1000 MHz. That's fine, if it can actually do it. In many cases it can, and if your memory has nice heatsinks then it is even more likely that it can do 1000MHz just fine with a voltage increase. If you have problems with the 3:1 ratio at 333 fsb, then you reduce the ratio. If you go from 3:1 to 2.4:1 then your speed goes to 333x2.4 or 800. If that helps you get a higher OC, then do it. But ideally you would try to aim for a whole number ratio, such as 3:1. Or if you go even higher with your fsb, say 400MHz, then a 2:1 ratio would be great. I only see maybe a 1% loss of performance from having a non whole number ratio.

At 290 fsb I would try to hit that 3.0 mem ratio. Any decent PC2-6400 should be able to hit that.
 
thanks , people.
...that was still Chinese to me. (assuming i do not know chinese).
i still dont understand how do i make sure the FSB😀RAM ration is whole number.
what do i divide in what?

my cpu bus speed is 333mhz now (OCed) and if i look at the memory tab in cpu-z than i see my Dram frequency is 333mhz as well (it's shifting slightly).

1 -does that mean im OK? (temps are at 70 celsius , tops). stock voltage. not more.
in CPU-Z it says FSB😀RAM 1:1. that's an indication that im good, right?

2 -now, if my CPU was to be OCed to 355 (to get a 3.2ghz, which is the highest i've heard my Q6600 should go) than how do i calculate my memory frequency?

(my memory stick is a single DDR3 , 1333 \ 1066. dont know the other.... um, specs of it).

3 - if, right now, im set at 1:1 with my mem multiplyer at 2.0, will it help if i up the memory multiplyer to 4.0? will it mean i am at ration 2:1?
also, will that help performances?!

4 - will it help if i buy a second identical mem stick?! Zap said that having one stick bottlenecks my performances. will it have a noticeable change?!


p.s. - i dont have some fancy cooling. it's all stock. an im not interested in high OCing. just to get as much as i can from the stock parts i already own.
so i dont want to up the voltage of my PSU. not if it puts my hardware at risk.
 
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To answer your post:

Your FSB:RAM ratio is 1:1, so your memory is running at 666 MHz because it is Double Data Rate (333x2). If you set it to 355, it would be 355x2, and so on. Temperature maximum for B3 Stepping Q6600 is 62.2 deg, and G0 stepping is 71 deg according to Intel's website. Depending on which one you have, you're either going too far with it or cutting it really close. If you're not at stock voltage, lower your voltage. Or just get a better cooler.
 
😱 dont worry so much about overclocking if you only have one memory stick. You need that 2nd memory stick because it will double your memory bandwidth. Many things will run much faster with two memory sticks. It should be the same exact size and brand. Read your mobo manual to make sure you are putting the 2 sticks in the right slots to enable dual channel mode.
 
azemsiB said:
To answer your post:

Your FSB:RAM ratio is 1:1, so your memory is running at 666 MHz because it is Double Data Rate (333x2). If you set it to 355, it would be 355x2, and so on. Temperature maximum for B3 Stepping Q6600 is 62.2 deg, and G0 stepping is 71 deg according to Intel's website. Depending on which one you have, you're either going too far with it or cutting it really close. If you're not at stock voltage, lower your voltage. Or just get a better cooler.
Click to expand...

im not sure. in cpu-z it says

stepping - B
revision - G0

so... what does that mean?


and i am also curious about my questions no.3 and no.4.

heres no.5) how can i measure the performances of my CPU? what benchmarks should i use?

with the OC i have now, at 3ghz, 3Dmark shows im getting LOWER score than with no OCing at all (in the cpu tests of AI and physics). their website claims im supposed to be getting around 8500 or so and im getting 7500 or so.

but in a benchmark by "geekbench" i get higher scores. it claims i should be getting a score of 3500 and im getting 4200.

p.s. - yeah. i tried reading the tut but maybe because english isnt my native tongue and im so new to computers and hardware i found it a bit too cumbersome and too often felt i needed to ask questions :\
 
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topeira said:
whatever i set it to i get lower score with 3Dmark.
Click to expand...

It could be that whatever you do causes the motherboard to run at a lower memory multiplier. Since you are running only a single stick of RAM, you are memory bandwidth limited, so anything that reduces memory bandwidth will impact performance.
 
^ In OP's other thread, he had crashing & overheating. So yes, overclocking your system to the point of instability, & without sufficient cooling, will reduce performance.
 
topeira said:
im not sure. in cpu-z it says

stepping - B
revision - G0

so... what does that mean?


and i am also curious about my questions no.4 and no.5.

heres no.6) how can i measure the performances of my CPU?
with the OC i have now, at 3ghz, 3Dmark shows im getting LOWER score than with no OCing at all (in the cpu tests of AI and physics). their website claims im supposed to be getting around 8500 or so and im getting 7500 or so.

but in a benchmark by "geekbench" i get higher scores. it claims i should be getting a score of 3500 and im getting 4200.

p.s. - yeah. i tried reading the tut but maybe because english isnt my native tongue and im so new to computers and hardware i found it a bit too cumbersome and too often felt i needed to ask questions :\
Click to expand...

You have the G0 which is the Q6600 of choice. Check the VID in Core Temp. The lower the VID the better (in theory) the chip should be. If you are using PC6400 DDR2 memory, it is tuned to run at 400mhz (800mhz effective). If you are running at 333x9 with 1:1 fsb/ram ratio you will get lower scores in benchmarks heavily tilted towards memory performance. What you need to do is find out what your maximum safe FSB is. Drop the multiplier to 7 and raise your FSB untill you reach its limit. If you are lucky and have a low vid chip you may or may not be able to get to 400mhz. If you can get 400mhz , raise the multiplier to 8 and you would have 3.2ghz and with a 1:1 fsb/ram ratio your memory would be running at its stock 400x2 (800mhz). What motherboard are you using anyway? With the wrong one, all this work will be in vain. Watch your temps and voltages.
 
my VID is 1.162 - 1.275.

how can find out what my safe FSB is? i've read around that others got to over 400. i dont want nor need to get that high. still , the 1:1 ration calculations elude me.

i get this far in fathoming the subject -
- if i set the mem multiplier lower means that my memory runs worse. i should try to get it to a higher multiplier.
- in order to get better mem multiplier i should lower the cpu clock ration to lower than 9.
- the lower i get the CCR the higher i need to set the FSB. so if i aspire to get to 3ghz on a higher mem multiplier i should set the CCR to X8 and the FSB to 375.... but i dont know what i should set the mem to....

how do i know what my dd3 memory's frequency\speed is?
what should i set it to match a 3ghz on a multuiplier of 8?

me confused = headache.
 
The reason this 1:1 ratio stuff eludes you is because DDR memory works with clock doubling. So you are running into semantical obfuscations. When someone is saying 1:1 they really mean 2:1. For example if you set your fsb to 333 and you set your mem ratio to 2:1, then your memory runs at 333MHz, which gives you DDR667. (It is confusing, and you have marketing people to thank for it.) For another example, if you set the ratio to 3:1 and your fsb is 222, then your memory runs at DDR1333.

But none of that even matters if you arent using two memory sticks

If you have DDR1333 and 333 fsb, then just set the ratio to 2.0.

topeira said:
with the OC i have now, at 3ghz, 3Dmark shows im getting LOWER score than with no OCing at all (in the cpu tests of AI and physics). their website claims im supposed to be getting around 8500 or so and im getting 7500 or so.
Click to expand...

Wait a minute wait a minute.... are you getting 8500 without any overclock, or is some random website saying you should be getting 8500 with no overclock? Big difference there? Have you run the test on your computer with no overclock? Because I bet its even worse since you only have one memory channel. Like maybe 6500 lol.
 
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@SM625 -
my memory is DDR3. i am supposed to multiply the numbers 3 times, no?
also 3Dmark tool says im supposed to get 8500 yet i am getting 7500 with OC. but im getting around 8500 without OCing.

so the calculations should be like so?:
FSB 375 X cpu clock ration X8 = 3000ghz
and this should go with -
MEM frequency ??? X mem multiplier ??? = 375?!?

if yes than what should replace the ???
i assume that if u correct this example i gave and fill in the questions marks with numbers than i might understand this mess.
(again, my memory is 4GB, DDR3 1333. not sure about it's frequencies

about my mobo - i have clue on how to check what mobo it is. gigabyte is calling it "ultra durable 3". that's all i know :\
in the bios i have an AUTO option to the right of the stock frequency of the memory. it changes as i change the FSB.
should i always try and get the multiplier so the speed on the right is EQUAL to the stock freq'? which is 1333??
is THAT the point of these calculations? if so than i can just play with the options i get until i see the result and it's 1333.



but from a lot of the responses here i get the feeling that the best thing i can do is just buy a new memory stick, right?
will this give me good improvement even on none OCed system? for 60$ im willing to give it a go if u think it's a good idea.
im not trying to OC just so i can boast about the numbers. i wanna OC so certain games will work better. if i can get a good result without OCing and heating up my hardware than i wont OC. if buying a new memory stick will get me where i want than perhaps OCing is not necessary.
but i'd still love to understand it so i can give it a go and see what happens.
 
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topeira said:
@SM625 -
my memory is DDR3. i am supposed to multiply the numbers 3 times, no?
also 3Dmark tool says im supposed to get 8500 yet i am getting 7500 with OC. but im getting around 8500 without OCing.
Click to expand...
No. DDR = Double Data Rate. That means multiply by 2. The name comes from the fact that you can pass 2 bits of data per clock cycle.

The "3" in DDR3 just means that's the 3rd generation of DDR memory.
 
topeira,

Your VID should be one number as reported in Core Temp ( never seen it listed as a range).
Your motherboard model and chipset is on the CPU-Z mainboard tab.
In the Gigabyte bios if you see Auto voltages, change them all to normal if running at 9x333 except for RAM (run as rated). Gigabyte boards will overvolt when you overclock when set to auto. No way should you come close to 70 degrees at 3Ghz with that chip unless you are running the stock HSF. Check those temps again with normal selected. Whatever you use to check temp, see if tjmax is set to 100 degrees.
 
boochi said:
You have the G0 which is the Q6600 of choice. Check the VID in Core Temp. The lower the VID the better (in theory) the chip should be. If you are using PC6400 DDR2 memory, it is tuned to run at 400mhz (800mhz effective). If you are running at 333x9 with 1:1 fsb/ram ratio you will get lower scores in benchmarks heavily tilted towards memory performance. What you need to do is find out what your maximum safe FSB is. Drop the multiplier to 7 and raise your FSB untill you reach its limit. If you are lucky and have a low vid chip you may or may not be able to get to 400mhz. If you can get 400mhz , raise the multiplier to 8 and you would have 3.2ghz and with a 1:1 fsb/ram ratio your memory would be running at its stock 400x2 (800mhz). What motherboard are you using anyway? With the wrong one, all this work will be in vain. Watch your temps and voltages.
Click to expand...

For reference, my VID is 1.325v and my first step was dropping the multi to 6 and raising the FSB to 400 giving my the stock 2.4ghz with the FSB/mem overclock i wanted. My CPU did all this at the default 1.25v. Then i raised the multi to 7, and needed 1.3125v for stability. Next, multi to 8, up to 1.5125v without LLC for stability (only 1.425v with LLC).

I ran some benchmarks and actually got higher throughput NOT using the 1:1 800mhz divider. I've posted the details in another thread last week.
http://forums.anandtech.com/showthread.php?t=2165134
 
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