PDA

View Full Version : Overclocking, is it worth it?


ATOJAR
09-18-06, 06:25 AM
Ive been thinking about overclocking my cpu BUT ive been wondering is there really any point? how bad is the damage overclocking actually does to your cpu in the longrun? and how long is a overclocked cpu actually expected to last before it dies? would you say you notice much of a difference?

I used to have the 64 3700+ 2.2 san diego 1mb cash, i overclocked this to 2.95GHz but it was unstable lol, however i did manage to get it running at 2.8GHz stable. to be honest i cant say i noticed a difference apart from a slightly higher 3DMark05 score!

One thing ive never really understood is the ram devider? when i overclock i just set my ram to auto and it usually runs ok.

I set the cpu multipliyer to x11
The voltage to 1.45v
hypertransport technology to x3
and the cpu fsb to 254(if i remember correctly lol) the result was 2.8GHz
well this was on the 3700+(never tried to overclock the x2 4200+ yet)

Like i said im not to sure about the ram devider and how this works, anydoby know where the devider in on my motherboard?(see the sig for my board) anybody shed some light on this please?

Would you say overclocking was really worth it?

nekrosoft13
09-18-06, 06:49 AM
i would say its worth it.

performance improvement is always good.

especially when you set your memory correctly, at 265mhz fsb, i'm getting some great memory performance.

yes, the life of the parts will decrase, but its nothing you or even next two owners have to worry about, it simply is not a big factor.

ATOJAR
09-18-06, 06:57 AM
Well i though sod it ill give it a bash.

Hyper transport frequency : x3
Ram timing mode: auto @ 333MHz
CPU frequency: 245
CPU multiplyer: x11
CPU voltage: 1.450v
Heres the results....

nekrosoft13
09-18-06, 07:01 AM
if your memory is rated at cas 3 at 200mhz, don't expect much

ATOJAR
09-18-06, 07:06 AM
if your memory is rated at cas 3 at 200mhz, don't expect much

Guess this is a bad thing then? its kingston 400MHz PC3200.

nekrosoft13
09-18-06, 07:08 AM
not every PC3200 is the same.

thats why some cost twice as much.

point is to either buy DDR400 at cas2, and then OC until you hit cas3

or if you want to have a safer bet at 250mhz fsb, then buy DDR500.

ATOJAR
09-18-06, 07:11 AM
I take it that the MHz of the ram is the timing?
In my bios i have:
AUTO
200
266
333
400
And so on....
My ram is 400MHz but i have it in the bios on auto, any ideas what it would be best to set the ram at with my cpu overclock? the higer io overclock my cpu the more i lower the speed of my ram is this correct?

nekrosoft13
09-18-06, 07:15 AM
no timings are CAS/tRCD/tRPD/tRAS

here i found some good info for you.

"Addressing memory is much like reading from a large, multiple page spreadsheet. It doesn't matter how quickly you can read, before you can start you have to find the page the data you want is on (this is known as tRAS), work your way to the row and column the data's stored on (tRCD), when you've found the cell you want it takes some time before you start reading (CAS) and when you get to the end of a row you have to switch to the next, which takes time (tRP).

tRAS is the time required between the bank active command and the precharge command. Or in simpler terms, how long the module must wait before the next memory access can start. It doesn't have a great impact on performance, but it can impact system stability if set incorrectly. The optimal setting ultimately depends on your platform - the best thing to do is to run Memtest86 on your system with variable tRAS settings to find the fastest setting for your system.

The tRCD timing relates to the number of clock cycles taken between the issuing of the active command and the read/write command. In this time, the internal row signal settles enough for the charge sensor to amplify it. The lower this is set, the better - the optimal setting is either 2 or 3, depending on how capable your memory is. As with any other memory timing, setting this too low for your memory can cause in system instabilities.

CAS Latency is the delay, in clock cycles, between sending a READ command and the moment the first piece of data is available on the outputs. Setting CAS to 2.0 seems to be the holy grail with memory manufacturers, but the difference between tight timings and high memory bus speeds is an arguement that we hope to settle over the course of this article.

The tRP timing is the number of clock cycles taken between the issuing of a precharge command and the active command. It could also be described as the delay required between deactivating the current row and selecting the next row. In conjunction with the tRCD timing, which relates to the time taken between the issuing of the active command and the read/write command, the time required to switch banks (or rows) and then select the next cell for reading/writing or refreshing is a combination of the two timings.

The Command Rate timing is another timing that is important to maximum theoretical memory bandwidth. It's the time needed between when a chip is selected and when commands can be issued to the selected chip. Typically, these are either 1 or 2 clocks, depending on a number of factors including the number of memory modules installed, the number of banks and the quality of the modules you've purchased. The majority of memory available today is claimed to run at the faster 1T memory timing.

Memory latencies are normally quoted in the following format, CAS-tRP-rRCD-tRAS Command Rate, an example being 3.0-4-4-8 1T, with the numbers corresponding to the individual latencies quoted in clock cycles. Lower numbers are better, though in theory tRAS should be tRCD added to CAS Latency plus 2."

Xion X2
09-18-06, 01:40 PM
The memory divider is just another way of fine tuning your overclocking ability. Say, if you needed to cut your memory speed down just slightly but didn't want to mess with your CPU frequency/overclock, then you would set a 5/6 divider on your memory. If the memory was originally at 600mhz, it would drop it to 500mhz. That's a rather poor analogy, but the main point is to illustrate how the divider works. It just offers you more flexibility when overclocking. Not all motherboards have this option, however.

The trick is to sync your CPU multiplier, memory speed(mHz), Hyper-transport speed (or bus speed) and your memory timings all to your processor overclock to get the best results.

Here's an example:

Your setup (theoretical):

DDR 500 memory
Athlon 3700
AMD mobo HT1000

Your hyper-transport speed is defaulted to 1000. There are two ways to overclock your processor: by increasing the frequency or increasing the multiplier. Every time you increase the frequency, you increase the bus (or HT) speed as well. Basically, it's a good idea to drop the hyper-transport multiplier down to 3x or 4x if you plan on doing some serious overclocking, because it needs to stay close to 1000 or performance can suffer.

Along with dropping your hyper-transport, you should also drop your memory speed to give you some headroom with overclocking your CPU. If it's 500mhz at default, drop it to 400 or 333. It's not likely you'll get a 500-600mhz overclock out of a processor if you start out at the default memory speed; it will just overclock the RAM too far past and create instability.

It takes a little experimenting to get a handle on all of this, but you'll get it after a while. It's really not that difficult if you've done the research on the capabilities of your system and know generally what you can expect.

nekrosoft13
09-18-06, 01:48 PM
don't drop the momery, if you don't have to, i got it stable at 265mhz, and i'm happy with that.