Share some knowledge with the rookies

dstyle347

I don't want to be real specific so other people will benefit from this.

There are a ton of directions to go when beggining to learn about overclocking. What tutorials should I read and what info is necessary to research the process for your personal application?

What is a reasonable expectation for performance increase, is it a set number or a percentage of stock?

Is there a performance increase ratio that should be targeted that will balance the risk with the performance gain?

I'll read up the suggested material before I ask anymore questions.

thanks,

Thrax

Overclocking is the grand art of <i>logical stabs in the dark.</i> That is to say, when you take a look at a set of components, you can gather a feeling about what that component can do by the information on it or by experiences of others.

I know, for example, that I can get about 2.4-2.6GHz out of a Winchester Athlon 64. I know that a JIUHB Athlon XP or a mobile Barton/Thorton will do about 2.3-2.6GHz with ease. I know that modules based on Samsung's TCCD chips can easily hit 250MHz on light voltage increases.

When I know these things, I immediately set my overclocking target for the lowest of the typical range.. Then it's a matter of finessing the CPU/RAM/Video Card up from there with fiddly combinations of voltages, multipliers and frequencies. The performance increase as a result is directly correlated with the quality and overclockability of your components; some components are more likely to give you a linear percentage increase though -- For example, the Athlon 64 is very good at delivering a performance increase equal to the percentage points in your overclock; from 2000MHz to 2200MHz is a 10% overclock, and the Athlon 64 will return a 9-10% performance increase as a result. Memory is a less exact science, as increasing the FSB from 210 to 220 might not give you the same result (It might be slower, actually) than if you increased it from 210 to 219; it's very much guess and check.

Video cards are so damn random in their overclocking that the best way to go is to start upping core/memory by 10MHz increments until you get little sparklies on 3d rendering. Then start backing it down by 2MHz until they go away; when they go away, you've overclocked your video card as far as it will go without cooling increases.

Risk/performance gain is a trickier question; generally speaking, if the computer boots up and runs and passes all your stress tests, then you're not at the damage point. Where this could go wrong is with memory, which will absorb a lot of voltage and still run, but might it might be damaging in the process. Always use the lowest voltage your memory will take to hit your target FSB speed - if you have to go above 3v, it's a good idea to get some airflow on it with an 80mm fan mounted in any crazy manner you can think of.

When overclocking memory, you have to balance timings with speed. The best thing to do is lower your CPU multiplier until it hits rock bottom, then at the loosest timings possible (3/4/4) see how fast the memory can go on stock voltages. Then up it .1v and see how fast it can go, then up it another .1v, then another until about 3v where you have to add cooling. Then once you've got your maximum speed, benchmark it and right the numbers down.. Then try to tighten up the timings, 3/3/4, then 3/3/3, then 2.5/4/4, then 2.5/3/4, then 2.5/3/3. Benchmark each set, and record the numbers each time. If you hit a certain timing combination that doesn't work at the frequency you've selected, try lowering the frequency and seeing if your tighter timings produce better results than the higher frequency with looser timings.. Only your computer, and you, can decide which combination will work best for you. Similarly, when overclocking your FSB, you have to find out eventually what your CPU will take (Particularly with the Athlon 64, where FSB overclocking stresses the memory controller) -- both in terms of the FSB and the core speed. Once you've gotten a target speed on your memory, slowly bump the multiplier up until the computer won't boot - then increase the voltages slightly (Generally a max of +.3v for any given chip, but this is not a set rule) until the CPU requires additional cooling or has hit its clock ceiling.

Once you fiddle with computers a lot, and read messageboards, you begin to derive an intuitive sense about components; you know what chips overclock well, what ones don't. You know which motherboards are good overclockers, and which ones aren't. You know where to buy certain components from because they're the most likely to ship you the newest version of that component, and so on.

It's 90% foreknowledge, 5% guessing, 5% luck.

dstyle347

How about the AMD and Intel differences when overclocking?

Thrax

Intel CPUs have no multiplier adjustments -- You can only adjust the FSB and a series of dividers; once your chip tops out, so does your FSB.

Athlon 64 chips can only have their multiplier adjusted downwards.
Athlon FX chips can have their multiplier adjusted in any direction.

Both platforms can reliably hit 250MHz.

The Athlon XP generally doesn't top 230Mz FSB without voltage modifications to the motherboard itself. With a mobile chip and an nForce2, the multiplier can be adjusted in any direction. Tight timings matter more on an Athlon XP than any other chip; timings don't much matter at all on the A64/FX/P4.

EMT

I was concocting some sort of response to this huge question but when I saw Thrax had caught the thread I took a break to see what he'd write. Nice technical detail, good explanation. I'm just gonna add in a broader way: the answers to the questions dstyle posed are It Depends. It's not simple enough to generalize any figures on general OCing. Any component can overclock some, but there's a million and one factors in how far you can overclock. They can be categorized -- even prioritized, I suppose...
1) What you're OCing
2) Cooling setup (Stock aka "what came with it" often won't allow much headroom)
3) Other components (It's one big system)
4) Electrical modifications (very advanced)
Once you know these, there's generally some max speed you can achieve, and it's a matter of "simply" finding it. This takes experience with the parts and/or software to do in a reasonable amount of time; you might substitute a lot of reading on the Internet for hands-on experience if you want to do a lot of research before buying stuff.

Final notes... The easiest component to OC is the video card. You can do it from within Windows. And be careful, but not fearful... very rarely does anything break while you're trying incremental OCs.

Oh, as for literature on overclocking in general, I'm not aware of anywhere towards which to point you. Usually you try to look up someone's experience on the same project as yours.

madmat

Well, basically everything he told you about multipliers DOESN'T apply to Intel chips simply because they're locked...period, no tricks, stunts or socket jobby you can try will unlock one either.

You might get extremely lucky and find someone selling an "ES" chip which is an engineering sample that is unlocked but they are rarer than hen's teeth but as to the OC darlings of the Intel crowd you'll find that the 2.4C and the 2.6C are the ones to look into, they get very good OC's with the proper board and ram, I'd suggest an Abit IC7-G MaxII board or the DFI Lan Party 875Pro B as both of these boards offer pretty decent OC options.

Since you're basically stuck boosting the FSB on an Intel rig you will want to look into the fastest DDR you can find (unless you decide to go the LGA 775 route and those boards use DDR2 mainly) which is PC4400 at the outside, Corsair and I believe OCZ sell lower latency versions now that are capable of 2.5-4-4-7or8 which really don't make much difference in all reality but can give you a marginal boost in bandwidth.

The overall advice that Thrax imparted upon you about the stratagey of OC'ing does apply though, follow his advice, shoot for the middle ground of the range that your particular combo is capable of to start with and go from there.

I personally set my ram to 2.8v and just leave it there and lock the AGP/PCI bus at 66/33 and turn the juice up on the vCORE by .1v when I begin OC'ing, I will usually go up 5-10mhz on the FSB at a time, 10 the first time and 5 the second and third until it begins to freak loading windows or hang altogether. Then I bump the vCORe up another .05v and continue on but you might want to make sure you've got killer cooling before trying that method as a stock cooler might fail you really fast.

I think if you ask 50 different people for recomendations on how to OC you'll get 50 different answers, some people take a conservative approach, some go balls out and some take the middle ground, I prefer the latter.

Good luck on you endeavors and may you never fry your CPU.

dstyle347

I have an adjustment interface for
CPU multiplier, CPU Vcore voltage, CPU frequency stepless control, AGP/PCI Freq. control.

Which of these adjustments would be involved when running Intel as opposed to AMD if any.

What literature should I read to address my obvious ignorance about all of this?
It would be better to have a general understanding before rolling off blind questions.

for reference I am attempting this with
P4 2.4c prescott 800mhz
ASRock pv488 - VIA pt880
2*256 kingmax 3200
aopen fx5500 128mb

dstyle347

Ok, so it seems general research will get me the basics, cover the nomenclature and broadly define procedure. What information do I take into account when trying to find discussion of a similar project, just the basics as I have posted above or is there more?

madmat

Don't mess with the multiplier, that's a good way to end up having to reset the CMOS, which is a bad way to start off.

A P4C is not a Presscott...that would be a P4E and as far as I know you won't be finding very many 2.4E's out there, I've only seen them offered by one site and that was like late last year/early this year, I'm not certain which.

With the PC3200 you have you'll most likely have to use a divider to get a decent OC because value ram usually doesn't like being pushed very hard, at 250FSB with a 5/4 divider the ram will be at it's default speed of 200mhz, leave the cas settings at "by SPD" to begin with and set the divider at 5/4 and begin bumping the FSB up a bit at a time, I won't try to tell you what to expect with that particular chipset as it's still a dark horse to me.

dstyle347

my mistake the old CPU was prescott, the 2.4c is northwood right? Is there an advantage or disadvantage associated with these core types as far as overclocking?

madmat

The Northwood runs a bit cooler, has less overall headroom but is more effcient as it has less stages in it's pipeline.

I have the 2.4C as well, I'm hitting 270fsb (when my pc works) and it's very stable at that.

dstyle347

thanks for everything so far, I have to go read up and get a better grasp of the general process before I make myself feel really dumb and repeat myself. Hopefully people continue to post for all us cherries out there.

muddocktor

dstyle, like madmat said about your mobo, that mobo and chipset is pretty much a dark hose here as to overclocking because almost all of us Intel overclockers are running boards that use the Intel i865 or i875 chipsets and not the Via chipset. From what you posted though, it looks like Via at least attempted having a pci/agp lock on that board, although if it actually works is another question(Via's not really known for having working pci/agp locks until really recently). The multiplier adjustment won't do a damn thing for you with Intel for the reasons already stated here; Intel locks the multiplier and there's no way around it. Your Northwood 2.4C should be a good candidate for overclocking though; there's a lot of headroom on all Northwood 2.4C procs. Mine runs 24/7/365 at 275 fsb/3300 MHz and will run even higher; I have it backed down to there for utmost reliability because my folding farm uses it as the gateway computer for my satellite broadband and everything has to communicate through it while I'm at work offshore.

For cooling my Northwoods, I use either the SLK947-U or SLK948-U heatsinks made by Thermalright along with either the Thermaltake SmartFan2 or the Delta FFB0812SHE focused flow fan on a Vantec Nexxus fan controller, so that I can control the fan speeds. Even the Northwood procs emit a lot of heat and are actually a bit harder to cool than AMD procs, but it's not unmanageable though.

As for max vcore voltage on Northwoods, even with good cooling I try to keep it at 1.65v or less; anything much over than that and you stand a good chance of your Northwood suffering from SNDS (sudden Northwood Death Syndrome) where it just dies on you for no reason(other than just too much vcore). This has happened with very well cooled procs too, so it's really just heat related. I will say though that both my 2.4C and my 2.6C could both get to 3000 MHz with stock vcore.

There is a bunch of great overclocking advice here in this thread so when you get the urge to overclock, reread these posts and give it a try.

mudd

Bone

well ive done my memory timings i have em at lowest and its all stable and i havent had to increase voltage which is awesome its 2-6-2 or however u say it like

row precharge time = 2
Ras pulse width = 6
Ras to Cas delay = 2

thats the lowest my mobo let me go

and my cas latency is at 1.5 its all working awesome. I overclocked my cpu like a year ago but i didnt see a peromance increase so ti wasnt worth it and same with video card there wasnt any like epromance incrase so i dont bother.

dstyle347

OK, So Im going to up my CPU host freq. right? say from 200 to 250? how do i set the divider and what should my cas latency be set to with options of 2, 2.5, or 3.

Bone

no... this is the way it works for CPU oc'ing

go into your bios
then go to like where it says ur cpu speed and ****
go to front side bus for cpu
and bring it up like ummm 5 or something the higher kind fof ram u have also determines how much u can overclockin like pc-3200 will allow u to overclock more then pc-2100
now to find out what ur speed is after u over clock u take the multiplier and MULTIPLY it by the FSB
Now go test it out and see if its stable i tend not to use stablity programs and just use my comp as normal and see if any crashes occur
NOW if they do then your gonna either want to down clock it a ltitel and see if it works then OR raise ur V core my the smallest increment u can on mine its .050
now Vcore is what raises temps not raising the FSB so keep an eye on those temps and dont overclock to high or it wont post and u gotta clear CMOS.

---

now as for cas latency put it to 2 if thats lowest it can go mine can go down to 1.5 and keep stable but u want it as low as it can go but keep it stable. and u want

Send a message via MSN to Bone

Re: Share some knowledge with the rookies
well ive done my memory timings i have em at lowest and its all stable and i havent had to increase voltage which is awesome its 2-6-2 or however u say it like

row precharge time = lowest
Ras pulse width = lowest UNLESS YOU HAVE AN NFORCE 2!!
Ras to Cas dela = lowest

now go see if its all stable if not change ut cas latency. HAVE FUN OVERCLOCKING!!!! and keep an eye on those temps and you know any smoke pouring out of your machine :-P jk

dstyle347

in the bios setup utility it only has options to change cpu host freq to manual and adjust actual cpu freq. Those are the only options I get for CPU besides enabling the spread spectrum. what is that?

dstyle347

why can't i just change the freq. (which is the fsb isn't it?) up then multiply by the multiplier (12 on the 2.4c ) to get the overclock? I would try it but Im worried about the divider for the memory. I have no idea where that is, it's not in my bios setup utility (asrock pv488 - via pt880) also exactly what is cas latency?

Bone

.... u have put it to manual so u can change everything ur self. and no u cant change multiplier unless u unlock it and i wouldnt try it cause u could **** over ur comp so yeah... and i dont know how so go find a guide on how do it but u need a amd to do it i dont think intels can be unlocked hmmmm... but what is the freq? pherhaps thats fsb hmmmmm

dstyle347

i think it is the fsb cause it's at 200 mhz and i can set it to manual and bump it up. I cannot change the multiplier itself which is set at 12. Say that is the fsb for the cpu, will bumping this up hurt my memory? is that where the latency comes into play? how do i set the divider? i know i want 5:4 probably but where do i go to change the settings, it's not in my bios setup...

Bone

ok well this is how it works.

it does not hurt memory. what i said bout memory is like if u do memory timings like i said and its like not stable like the computer then loosen em up meaning like if u have it at 2 then make it 2.5 etc. and what divider do u speak of? and yeah im pretty sure thats fsb then the best way to check is to raise it and then go get zpu-z go do search on google and download it and it will tell u what ur current Mhz on cpu is so u cant ell if its overclocked :-P

muddocktor

dstyle, yeah that's the fsb speed. You can't change the multiplier though because unless you have a very rare engineering sample Intel chip, all P4 and P3 processors are multiplier locked. As far as for changing your memory speeds or engaging a pci or apg lock, I have no idea with your board and chipset.

Bone

well im guessing it is FSB then so try puttign it up some and get cpu-z search for it on google and see if ur Mhz changes accordingly. as for memory it shouldnt harm it but wha ti mean is if ur system is unstable before raising vcore. try looseing memory timings like putting cas lat at 2.5 instead of 2 etc. and what divider do you speak of?

dstyle347

cpu / memory fsb divider i assume. 1:1 or 5:4 i don't know? The freq was the FSB and I got it up to 245 before it crashed, I started over and now I can't go past 238. my memory is at 2,3,3,6 should it be 2.5? what exactly is the first number besides the only one I can manipulate with my bios setup?

muddocktor

That first number is the ram's Cas setting and try to set it to 2.5 or 3 and see what you can do. Plus, if you have vcore adjustments in bios you might try upping the vcore a bit over what it's stock setting is. If you do raise the vcore, watch your temps closely though. You can also raise the ddr voltage to 2.7-2.9v with no problems in a decently cooled case, if your mobo allows ddr voltage adjustment.

dstyle347

I am pissed. I either suck at this really horribly or I have a crap mb. The latter being more expensive to fix so I'm hoping it's just me. I can't get this thing stable at any OC to speak of, maybe 225 or some rediculous waste of time increment.

My MB manuals explain nothing, they're horrible and the website dos'nt help much either.

CPU freq or FSB at 233
multiplier obviously locked at 12
spread spectrum (??) disabled (other option enabled)
I have my sticks of ddr400 set to ddr333 on fsb to act as the divider.
Flexibilty option? no idea what that is... on or off?
Latency on 2.5 (2.0 or 3.0 are choices)
I have the dram voltage on normal (other option is high)
AGP voltage on high (other is normal)
dram command rate? (either 1t command or 2t command)
not able to change vcore (running at approx 1.54)

any suggestions besides an intel chipset?

dstyle347

Ok memtest just showed me that the memory i put in today to replace bad memory was worse. Thats the third time thats happened, I think I just cleared out all the crap memory from the newegg warehouse, no worries, I can wait another week to go to class (it's online and that was sarcasm). So that sucks, also the implied AGP/PCI lock was just that... implied, asrock tech support just confirmed that there is no actual lock. Nice, I think im gonna stick to my piece-o-crap e-machine in the kitchen cause that $1200 bright glowing blue noisy paperweight in my room is making me naucious.
Maybe I can OC this thing, anybody know how to oc an sx33 cpu with 16megs memory? maybe i should upgrade to the dx2-66 thats a screamer!

Bone

actually 200 going to 225 aint bad thats 300mhz more making ur 2.4ghz a 2.7ghz... whats wrong with that. if your on stock cooling on cpu and that ur expecting to much and also have u tried raising ur v-core but just keep eye on teamps? and make ur memory as loose as possible and i dont know what u mean by a divider can someone explain maybe im just noob >_<

Thrax

200 to 225 is a <i>drastic</i> leap for <b>most</b> memory - winbond BH5 at 2.5/3/3, or Samsung TCCD at 2/3/3 being the exceptions.

Bone

yeah if it is stable at 225 leave it and test it cause if so thats quite an improvement :-D good work on your first OVERCLOCK!!! in fact im doing a project on overclocking as my end of the semester thing for my computer app course we have to make a project in powerpoint and present it so i decided do overclocking when its doen ill upload it to net as a html so you guys can see it :-P

dstyle347

good deal, I could always use more material to read up on.

Thrax, your scaring me with the "drastic leap" what would be safe? When I OC ddr400 should I change the mb settings to 166mhz instead of 200? Would'nt that act like a divider? And could you explain the divider thing to me as well? Is it to seperate cpu and memory when oc'ing? how does it work?

My new memory is :
Manufacturer: Geil
Speed: DDR400(PC3200)
Type: 184 Pin DDR SDRAM
Error Checking: Non-ECC
Registered/Unbuffered: Unbuffered
Cas Latency: 2.5 7-4-4
Support Voltage: 2.55V-2.95V
Bandwidth: 3.2GB/s
Organization: two 32M x 64 -Bit
Special Features: Optimized SPD for Dual Channel DDR motherboards
Warranty: Lifetime