trying to learn to OC

[jba6511]

have been reading all the info I can on this forum about OCing in the last few days and now I have some questions. If attempting to OC an e6300 can the FSB be raised without having to change other areas such as the RAM timings? Is it possible to OC just the CPU? Also, I have 1Gb of G.SKill DDR2 667 (PC2 5400). Can someone try and explain to me what it means and the effect it has on raising or lowering the timmings. I am assuming you can switch from say 5-5-5-15 to 4-4-4-x in BIOS? Sorry for the newbie questions

 

[3Ball]

Well as far as just OC'ing the CPU the answer is no in a quick and easy answer, either way you will be highering you FSB, but you can technically higher your CPU and FSB without OC'ing the memory if you get the divider set correctly. Anyway you look at it, you will always be affecting atleast 3 things in one way of another: CPU Speeds, FSB, and memory speed. As for the timings. Well memory can scale only so far and you can think of memory timings as how long it takes the memory to complete a cycle per say. For example if one car with 12 inch tires and is rotating at 1000 rpm's in order for a car with 24 inch tires to maintain the same velocity it would have to rotate at 2000 rpms. That is similar to how ram timings work, which in comparison to an extent you could say 400mhz memory @ 2-2-2-6 is effectively similar to 800mhz memory @ 4-4-4-12. The higher the mhz the more relaxed the memory requires to stay stable. So just guess and check until you get the tightest possible timings at a good speed ratio, but remember that CPU speed is king over all other variables in overclocking.

P.S. Sry for the confusion, im sure this isnt very clear and I didnt do a very good job of explaining it, but im in the middle of like 4 different things right now, so hopefully someone else can come along and clean up my mess, but maybe this will help a bit to get you started. lol

Best,

3Ball

 

[jba6511]

so I could leave the default setting on the memory, which I believe are 1.8v and 5-5-5-15 and raise the FSB on the CPU? My aim is to do a mild overclock and get the e6300 around 2.4 if thats possible with stock cooling. So to do this would I just change the value * multiplier in BIOS for the cpu in small increments until I hit the desired speed. I understand that the multiplier in this case is locked and can not be changed.

 

[YodaOfBowling]

I am also no expert, but I believe I can help on some of your questions. As far as I know, the only way to OC just the cpu without OCing anything else would be to raise the CPU multiplier. The cpu multiplier is a setting (in the bios) that determines the speed of the processor by causing the processor to run at some multiple of the FSB frequency. For instance, if your FSB speed is 266 MHz, and the cpu multiplier is 7, then your cpu is running at 266*7=1862 MHz (1.86 GHz), which is how the E6300 works at stock speed (this can be confusing, because when you look at the E6300 it says it runs at 1066 FSB, and I just said it runs at 266..."Whats up with that?", you might ask...Well, this is because the FSB is running at 266, however it is "Quad Pumped", meaning that it transfers info across it 4 times per clock cycle, therefore the FSB runs at an effective frequency of 4*266 MHz = 1066 MHz). Now, the problem with raising the cpu multiplier is that the E6300 chip is locked at a multiplier of 7 and won't allow the user to raise it. Therefore you will not be able to use this method to OC the processor. This is why people usually raise the FSB frequency in order to OC their processor, because the processor always runs at some number (7 for the E6300) times the FSB frequency, so raising the FSB speed also raises the CPU speed.

The same is usually true for the RAM. DDR2 RAM normally runs at the same speed as the FSB, however, DDR stands for double data rate, meaning that it sends information 2 times each FSB cycle. So, if the FSB is 266, then the ram sends info at effectively 2*266 = 533 MHz. Hence you would want to buy at least DDR2 533 RAM with for a system with the E6300 processor. Now, again, we see that if the FSB is increased then the RAM speed is also increased (2*FSB). Now, I believe that in some BIOS there is a setting that adjusts the speed of the ram in the same way as the cpu multiplier, but in this case you can set the ram to run at a higher or lower speed than the FSB. You may have settings such as 1:1, 3:4, 4:5, 1:2, 3:2 (these are ratios of RAM:FSB...1 to 1, 3 to 4, 1 to 2 etc., which are exactly the same thing as a multiplier where the multiplier is now a fraction, such as 3/4, 1/2, 3/2 etc...also notice that these can either set the ram to run at less than the FSB (under clock), such as 3/4, or 1/2, or they can run the ram at higher than the FSB (over clock), such as 3/2, 4/3 etc.) Now I don't have any actual experience with changing these settings, so some other, more experienced people might be able to tell you how this setting might appear in specific BIOS...I unfortunately cannot. But in any case, the idea is the same: setting your ram to run at either slower or faster than the FSB by setting something like a multiplier.

Now, RAM timings, as I understand them, are settings that have to do with how quickly RAM reads and writes and stuff like that...however I could be way off...Anyway, I know the numbers represent how many clock cycles it takes the ram to perform certain functions, so bigger numbers mean that it takes more cycles (more time) to perform a certain function that it would take if the numbers were lower. Naturally it is more demanding on the ram to force it to do something in a shorter amount of time (or fewer clock cycles), so ram with "tighter timings" or smaller numbers is probably higher quality, and therefore usually more expensive. However, from reading on THG, it seems that the timings don't make nearly as much impact on performance as does overclocking the CPU (something like 2-5% performance increase, instead of the 20-50% increase you could get out of overclocking the E6300). Therefore, what most people do is as they raise the FSB speed (and hence the cpu and the ram speed), they also "loosen" the timings on the ram. Higher numbers in the timings allow the ram to overclock to higher speeds, and although you get a slight decrease in performance due to the raised timings, the corresponding increase in performance gained by a higher overclock far outweighs the decrease do to raising the timings. This is why buying ram that rated for at least the final speed (after overclocking) of the FSB is better than buying ram that just covers the stock FSB speed and then gets overclocked above the RAM's stock speed. So, if you buy DDR2 533 (meant to run at 266 MHz) with timings of, say, 4-4-4-12 and use that in your E6300 system and then overclock your FSB to 333 MHz, then you will most likely have to raise the timings to something like 5-5-5-15, and take a corresponding decrease in RAM performance. However, if you spend a little more and buy DDR2 667 (meant to run at 333) with timings of 4-4-4-12, then when you overclock your FSB to 333, you can keep it at 4-4-4-12 because it is only now running at it's stock speed. Oh, and yes, the timing settings would be found in the BIOS.

Hopefully this helps. You probably already knew a lot of this stuff already, but I just wanted to be thorough.

PS, the example of the 12 inch tires vs the 24 inch tires is actually backword...to keep the same speed, the 24 inch tires would have to have only half the rpm (500)...sorry, couldn't resist....but the idea applies, just swap the 12 and 24 and it's all good.

 

[jba6511]

thanks for taking the time to explain that to me. That was an extremely informative post on the subject. Answered some of my questions and explained it in a simple to understand manner. I still have some questions but that was a great start. Thanks again.

 

[3Ball]

Thx for the correction! Just gettin myself mixed up. lol well I can OC just not good at explaining to others.

Best,

3Ball

 

[opti]

mem timings explained:

http://www.amd.com/us-en/Processors/ComputingSolutions/0,,30_288_13265_13295%5E13335,00.html