Overclocking confusion.

Hi there, I've been reading everywhere to get the best overclock you need to set your RAM down to 133 or 166 when testing your CPU. Mine will only go down to 400, at its lowest.

When testing your memory you are supposed to set it to its 1:1 setting, however mine is 334.5 (DDR669), which is not mentioned by most of the guides I've read.

Also what i don't understand is how reducing your HTT multiplier and increasing your FSB would still overall increase your speed, because your losing 1x or more multiplication.

Sorry to be a total newbie, but i've never overclocked before, and theres a lot of stuff to learn, which is hard when its poorly described.

Thanks so much for your time!

what program are you using to overclock?

Varruious.

CPU-Z, SuperPI, Max95 Heat Test, etc. I can understand the overclocking, just some of thetheory behind it.

Also can't find the HTT frequency option in my BOIS, but its a very old version so i'm going to try updating it before i question that.

It sounds like you are getting some incorrect information somewhat. Or mislabeled perhaps. With the changes in AMD putting their memory controller on die and the advent HTT many have had this issue.
1. There is no longer a FSB(Frontside Serial Buss) in actuality, it was replaced with the HTT but they are similar so many mistakenly still use the same terminology. FSB settings in most motherboard bios options is actually your RAM speed setting. At one time CPU speed = CPU mulitiplier (multiplied by) FSB (or Ram clocking speed). This is still generally the case but HTT is a little different.
I don't know what all sites I can link here so I wont link any but suggest some to google.
XtremeSystems.org, ExtremeOverclocking.com, Overclockers.uk are all decent places for some hints and tips.

btw, HTT only has to be within a certain range and affects stability not your actual CPU clocking speed. My HTT was lowered to 3 to keep it in the "stable" range because my RAM is clocked much higher than stock.

Again time is also affecting your RAM settings. A couple thoughts, some bios options rate 100/133/166/200 and some rate 200/266/333/400. Believe it or not those settings are identical. I'm sorry if this is all confusing you more but it is the difference of DDR vs SDRam's change to the PC world way back. I assume you are using a newer PC with DDR2 ram that clocks at even higher settings.
Do some more reading(sorry to send you off for info but there are much better sources of info than myself, I don't OC hardcore anymore but used to).
The general guidelines you read are true.
To test your RAM's upper limits requires 2 things. First, as you found, lower your CPU's multi to eliminate the CPU as your top end in testing. Now raise your RAM(still called FSB) in increments of choice and test for stability(Prime95,memtest,HEAT, etc) and slowly work it up until you see errors. I personally let it run at that(in memtest off floppy or bios though NOT UNDER AN OS ESPECIALLY WINDOWS) at that level. Often, memory "burns in" and becomes stable(or more stable) by doing this. Now, about your HTT, like I said, it needs to be in a certain range. It is figured by your (again they still call it FSB but)your RAM speed setting mulitplied by your HTT. The HTT number is in large part IRRELEVANT to actual affect, it is the range that it falls into. Do some searches on your mobo/chipset to find its recommended range and keep within it. In simplest terms, you must lower your HTT to raise your RAM speed and still be in the stable area.
Checking your CPU's core clock is harder imo nowadays because of the locked multipliers on CPU's(excluding Engineering samples from Intel or AMD's top line models which are all fully unlocked). After you have found your maximum RAM operation speed back it off 10-15% and bring your CPU multi back up to stock or just under. You can always lower your multiplier, you just can't go above what the factory laser cuts anymore. Now start to fiddle. Try 9 * 373, 9 * 377, 9 * 388, or whatever etc. This time though I find Memtest less reliable and you almost need to boot into your OS for tests like P95.
The general way to accomplish your goal is the same as it always has been. However, some of the terms and actual devices are different.
GL and HF. OC'ing is fun, but in all honesty, the performance gains are rarely needed or even noticable with modern hardware. It's more about the knowledge, control, customization nowadays. I highly doubt I will ever see such great gains as my old K8 1.7Ghz clocking all the way up to 2.8 on air cooling. Even if I took the trouble of soldering varistats and rheostats to alter my motherboards voltage regulators, most modern CPU's are just closer to their maximum states already leaving a lower actual % increase in processing power.

Also, if you have a dual-core cpu these changes affect both cores. To my knowledge(and I don't keep up well anymore) you cannot clock the cores seperately(reliably) although you can set Affinity to run certain programs/applications on only one core.

Ah thank you very much.

My DDR2 ram can go up to 800Mz, so that'd be 400, which still sounds high but must be right.

Thanks for the infomation, very much. All i have to do know is find out where my HTT frequency options are in my BOIS, been looking for a while but to no avail, going to update my BIOS (its currently version 6, newest is version 14) and then see if i can find it then.

Thank you very much for your help, i know that OC'ing my machine won't make it run much faster, but like you said, its the experience, and becoming closer to my beloved rig.

Shameless plug!

http://forums.overclockers.co.uk/

To explain a bit more things and in a more organized fashion(imo).

The way AMD 64 cpu's do the memory clock is that they take the speed it's rated to run at, and divide it into the cpu speed. For example: Let's say you have a 2100mhz cpu and ddr2-800. It takes 2100 and divides it by 400(aka 800 ddr) and then rounds the number it gets UP to get the memory divider. Which in that case is 6. Which means your ram would be running at 350mhz(aka 700 ddr).

Some boards give you an option to set the divider higher and thus make the ram run slower at default. But the plus side to that is that you can overclock further without putting your ram over it's limit so easily.

The Hypertransport bus is only rated to run at 1000mhz on most chips(except the phenoms) so you generally have to reduce it when overclocking or your system will fail to boot when overclocking.

For example: My cpu is overclocked by roughly 35%. Which makes the HT base clock(the number in which is multiplied to get the cpu's speed as well) about 269mhz. The default HT multiplier on my chip is 5x. And Well, as you could probably guess without doing any math that that would far, far exceed the 1000mhz the ht bus is meant to do. Many boards WILL fail booting and revert to stock settings if that clock is too high, such as how mine fails if it goes past about 1040-1050mhz. So In order to increase the cpu speed further and still be able to boot normally you have to knock down the HT multiplier a notch or two depending on how high you're going.

The ht multiplier also does not effect the cpu core speed.

How much of a difference you see will really depend on what you do. If you run anything that is heavily cpu dependant and benefits significantly from a faster cpu you'll definitely see an improvement. Even more so if you have a dual core and the app is multithreaded. But if you don't do anything heavy like that you probably wont see alot, no.


Also I found this little guide to be kinda useful when first learning about how to overclock AMD 64 cpus: http://www.hardwaresecrets.com/article/102

Thanks a lot. I understand a lot better now. For some reason my BIOS dosen't appear to have an option to change the HT frequency.

I was wondering if anyone knew of a program to change the HTT ('FBS') from inside windows and save it to the BIOS? I have programs that allow me to temporally change it, but not permanently, and as i can't find HTT frequency in the BIOS, i need it to be permanent.

Welcome to the darkside.

Overclocking is like a drug. You start off telling yourself I just want a little bit better performance, and before you know it your trying to find out just how high you 3dmark06 score can go.

simple oc guide.
1. If you can not afford to replace it DO NOT over clock it.
2. more speed = more power = more heat
3. by the time you see smoke its to late.
4. no two chips will oc the same even from the same lot.

Alot of overclocking is done on motherboards that support it, not all motherboards and bios support overclocking. Overclocking almost always voids warranty.

Google is your friend.

Every machine I have ever ran overclocked for extended periods of time has resulted in dead pc parts. As Zamial said it is like a drug for a while until it turns round and bites you on the bum.

This may not be the answer to your question but please think carefully before venturing into the darkside that losing your pc is an option you are willing to take if things go bad.

The only way overclocking can harm your computer is by two means:

1). The extra heat generated causes large heat pockets to form on or near the heatsink to processor threshold, causing the delicate silicon wafers and interconnects to weaken and eventually breakdown.

2). The extra voltage required on some overclocks creates what we call "Puddles" That is where a pocket of electricity has a difficult time going through a gate in the processors pipelines. If this occurs too frequently in the same region, the electricity will fuse together the silicon atoms creating something resembling a puddle under a SEM. This then creates a heat pocket, but only this time, the heat pocket is internal as opposed to the above issue, in which case the heat pockets are superficial or directly under the processors heat cover.


If you can keep both of these in check with extremely good cooling, you will do no more harm to a stock PC.

full article--good read, and everyone trusts AnanTech.

Indeed, Anandtech is a great site. Anand is a very intelligent man. Look at my comments above as well.

My personal opinion:

Unless you enjoy the "hobby" aspect of overclocking, the small increase in "real world" performance is not worth the trouble.
By "real world" performance, I mean the actual perceived performance of the system as opposed to numbers spewed out by some test program.
By trouble, I mean the time, money and effort to set up the overclock (especially if it involves extra cooling), and the general system instability (which doesn't always show up right away).

QFT

stability>all

The newer chips can overclock 33% easily with no risk and only little increase in temperature granted decent airflow. And "hobbyist" overclockers do as much as 66% overclocking, I assure you, that's not a small increase and only at that amount would involve some extra cooling.

And isn't that what overclocks/benchmarking teams do? They strive for stability? If your overclock isn't rock solid stable, then you're obviously not doing a good job

What's the CPU mean to you? Is it worth the extra <40 USD for the aftermarket HSF and the 1 hour it'll take you to google how to lap your equipment?

The way I see things...

Even "if" OCing decreases the life expectancy of your CPU by as much as 50%, most people will have upgraded their whole systems and moved on by the time it may have failed.

I still have my P4 1.6A Northwood overclocked to 2.2ghz with no problems to this day.

second pc P4 2.26 ghz running happily @ 2.8 ghz (watercooled)
also another thing that affects overclocking is the cooling on the north and southbridge (northbridge only on older motherboards) but most are rather decent cooled nowadays and nr2 being the quality of you're DDR ram (second pc has Corsair XMS pro's in it, since those have the heatdispensers on it making another difference when you're rather high overclocking)

Another thing about overclocking is

1 don't do it if ya don't know what you're doing at the first place
2 if ya do take risks i hope ya got the money to replace the hardware that ends up broken while testing the overclock if you push the limits too far
3 nowadays it's less worth the effort on brand new CPU's, but it's great to overclock an older one (waranty voids after 2 to 3 year (amd 3, intel 2 years if i'm correct))

Hope that gives some info, Cyb3r