Beginners Guide to Overclocking

This is a very good guide. I've been reading Jokester posts for a couple of years and I've found him to be a great source of knowledge.

I'm waiting for parts (as per usual) so I can do yet another upgrade.

So while I'm doing that I'm reading up on overclocking so I'm not rusty, in case there's anything I don't know, or had forgotten.

There's some questions that commonly get asked that have arisen since the guide was written, specifically about temperatures.

Previously we used 2 main temperatures. CPU and system, as measured by motherboards.

The CPU temp is measured from (an unknown point, likely in the socket itself), but it was not inside the core of the CPU.

The system temperature is not as exact, and is some level of how warm the motherboard is in general. In some cases I think this is referred to as the chipset temperature, but I don't believe that A64s had the sensor in the NF4 chip. I don't know if the more modern Intel boards have theirs inside this.

My Abit board also has a VRM temperature sensor, most boards don't have a temp sensor here and it's of limited use.

A "new" way of meauring temperatures is with the on board sensors in CPU cores. Both AMD and Intel provide these in dual core CPUs. They may have provided them in single core CPUs, but I wasn't aware of them when I was using single core.

I'm not 100% clear on which CPU temperatures are supposed to be kept under what level.

Generally core temps are noticably higher than the CPU temperature the motherboard reads. As far as I know AMD and Intels maximum operating temperature for CPUs is not meant to be the internal temperature. Conversely Intel chips heat throttle based on the internal temperature.

If you want to expand your guide to cover the common questions on those Jokester it'd make it more complete.

The other thing not covered is the other voltages, some of which can be set in BIOS. Some of these I know what they are, some I don't.

HTV - Hypertransport voltage. I don't know if Intel boards have an equivalent. I also don't know if it has any effect on overclocking, assuming that the HTT multiplier is dropped to keep it under 1000 (or higher for boards with a higher HTT max).

DDRVDD - Just another name for memory voltage. Seems to be only Abit use it.

DDRVTT - Half of memory voltage is all I know. I don't know if it can help an overclock if it's higher.

CPUVDDA - Haven't a clue what this is. It's almost the same voltage as the ram voltage, but slightly lower - 2.59 compared to 2.53, at stock. Nor have I any idea what this is referred to on "proper :P" boards.
 
Yeah it could do with updating to reflect things like TAT/Coretemp. Problem with voltages is that each company tends to call say chipset voltage a different thing (and it doesn't help that you can now give the FSB, chipset, memory hub all different settings each with their own multitude of names).

Jokester
 
Jokester said:
Yeah it could do with updating to reflect things like TAT/Coretemp. Problem with voltages is that each company tends to call say chipset voltage a different thing (and it doesn't help that you can now give the FSB, chipset, memory hub all different settings each with their own multitude of names).

Jokester

Some kind of table which showed both the various different names used for each voltage, and what they can affect would be a great resource. But it'd be a bit of an undertaking, and something one person couldn't do easily on their own, since they won't own boards from all of the common manufacturers.
 
The Halk said:
Some kind of table which showed both the various different names used for each voltage, and what they can affect would be a great resource. But it'd be a bit of an undertaking, and something one person couldn't do easily on their own, since they won't own boards from all of the common manufacturers.

Sounds like a realy good idea and would be a great help when changing mainboards :)
Might be a good idea to start a special thread where people could post there mobo make/ model. And the voltage settings they have and if known what they relate to. For example my quadgt has a voltage refered to as cpu vtt which as far as i can tell is vfsb. It would just need some brave soul to compile it in some kind of table and roberts your mothers brother ;) Any volenteers???
 
No that's correct, when you're overclocking your CPU you want to keep your RAM as far as possible at stock speeds or less. Only once you've found the max CPU speed should you start overclocking RAM.

Jokester
 
Hi

I have overclocked by 7900gs stock as below but am wondering whether having the GPU core running at 80c under load is OK?
 
This seems like the right place to ask a stupid question.... :D

I'm trying to stress test my CPU (q6600), to see what the temps are like. I'm using Prime95, but max stress on the CPU is about 25/30%!?! I've seen some screenshots on here, and people seem to be running multiple instances to max out the CPU... How do you do that!?! :rolleyes:

Cheers
 
Does anyone have a copy of the PPL list for Clockgen please as it's not available the cpuid website at present? I need the code for a 2180 overclock :-)
 
Great guide, have been following it but my mobo has more voltage options. Do I need to touch any of these?

CPU VTT 1.2V Voltage
MCH 1.25V Voltage
ICH 1.05V Voltage
ICHIO 1.5V Voltage
DDR2 Reference Voltage

Too many options in the Bios!
 
\ive managed to get my Q6600 to 3.4GHz running at 1.4V at 66, 66, 61,61 degrees after 8 hours of prime (max heat test) what sort of temps on prime should i limit myself to?
how much farther does it look like i can push it?

Is it best to have the ram 1:1 with fsb? because ive somehow gone from 5,5,5,15 to 5,6,6,16 by upping the fsb and keeping the ram on 1:1?

Ive allso OCed the GTX what sort of temps under load should I keep it to and is several run throughs of 3dmark prove its stable?
 
Would anyone be kind enough to explain the RAM divider please? In this case...

setting the memory divider to 1:1 would have it runnin lower than its stock specs. 3:4 is the right settings for the ram at that speed. the ram you have is CellShock 2GB (2 x 1GB) DDR2 PC2-8000C4 1000MHz Dual Channel Kit
so your ram should be running at 500Mhz which it is. since your fsb is 375
375 x 4 = 1500
1500/3 = 500Mhz
which in effect is 1000Mhz DDR2, if you had the ram running at 1:1 it would be much lower.

The 3:4 bit makes sense as the 4 is the multiplier, and the 3 part is the RAM divider lowering the frequency to the 1000Mhz the RAM runs at.

But what does 1:1 do?
 
Back
Top Bottom