The Risks of Overclocking

[b0redom]

I actually set fire to a 7900GT once. Seriously. My machine was powercycling, so I took the side off to check that the fan was spinning, and saw one of the RAM chips flare and burst into flames.

I suspect that had more to do with me having a duff PSU than a monster overclock though....

Tom

[5lab]

Heat shortens chip life too, and when you increase the clock without increasing the voltage, you still increase the heat output.

i'd argue against that - intel used to warentee thier chips for 3 years @ 90C - i suspect its now the case too but i'm not that *into* hardware any more

sure, extreme heat kills a cpu, but has anyone got any *proof* that running at, say, 80 rather than 40 will make a cpu last less time?

[notsobig]

I have been overclocking my cpus since the day of pentium 166, but luckily I have killed none so far and they all still work. My latest overclock is 4000+@3.01G and I'm happy with the extra performance boost. Only downside I can see is that once you start overclocking and used to extreme speed, you have to pay a lot of money to get similarly performing chip at stock clock, which will force you to another overclock in the end and you will never get out of this endless loop

[YorkieBen]

heat shouldnt be a problem for cpus, all cpus now have thermal throttling afaik so they slow down before they get to a critical level.

If you are gaming then a cpu overclock is far less useful than a gfx card overclock - i have seen a very interesting comparison (cant remember which) that althought core2duo gave higher framerates than the Athlon X2s, it didnt really allow much the way of higher details etc because framerates are far more dependent on gpu

[BlindMelon7]

I managed to get my 3200+ up to just over 2.4 whithout changing voltages. I'm scared of changing the voltages with my current power supply as its a bit dodgy so i'm waiting for my new one. I'm hoping to get it to 2.8 at least.
As for my graphics, I clocked my onboard from 350 (its max default setting) to 500! It was really easy as well

[Clstrphbc_donut]

Never actually broke anything overclocking, even though I pushed my 2.4GHz P4 from 2.8 to 3.6....it just wouldn't boot.

[iranu]

This is a genuine question not a dig or anything but...

is overclocking really worth it? I mean, is the difference that noticable?

£100 opteron 146 usually clocks at 2Ghz. Mine is at 3Ghz and more than happy which at the time was giving performance of a £650 processor. And yes I do notice the difference, not as much as going from 1Gb ram to 2Gb. So yes it is worth it if you know what you are doing.

All the horrible stories are either from people who have loads of money and buy a processor/graphics card each month and see how fast they can go or they are from people who didn't know what they were doing and pushed things too far too quickly.

[oralpain]

Athlon64s do not have thermal throttling, though some motherbaords for them do.

This is a genuine question not a dig or anything but...

is overclocking really worth it? I mean, is the difference that noticable?

My A64 3000+ is 1.8GHz stock. I have it running at 2.715GHz, 24/7 stable (72 hours of prime95, no problem). Above regular cost, I needed a 40 dollar heatsink to do this. CPU has been running at around this speed for 14 months.

My 7900GS ($165 MSI, the cheapest one I could find) was factory clocked at 500MHz core, 700MHz memory. I put 70 dollars worth of air cooling (core, memory, and votlage regulators) on it and volt modded it (with a #2 pencil and conductive paint) a reasonable amount. Now it is stable (no throttling, artifacting, crashing, in anything) at 710MHz core, 909Mhz memory. In games that don't typically utilize over 256MB of texture memory, this 7900GS is slightly faster than a stock 7900GTX. The card is new, so long term reliability is still somewhat questionable, but I suspect it will last as long as I need it.

My year+ old TwinMOS 2x512 PC3200 DDR (cost me all of $90 usd for the gig), rated at 200MHz 2.5-3-3-8, has been running fine for well over a year, passively cooled, at 246MHz 2-3-2-7 (with all other timings virtually as tight as they can go), with 3.16 volts. With more cooling and enough voltage, DDR600 could be a distinct possibility, with similar timings. Winbond revised CH-5 UTT chips where one of the greatest overclocking bangs for the buck ever.

This is all in a $70 ($95 if you count the vantec heatsink I put on the chipset) DFI NF4-DAGF motherboard that does 301+MHz external clock, 24/7 stable.

My $65, 420w Enermax PSU (something like 32-36A total on the 12v rails) is perfectly sufficent to power all of this.

Most of this PC is over a year old. I built it to overclock, with total stability, on the cheap and it did. At the time it was much faster and much less expensive than the new computers of many of my aquantances.

Yes, it's worth it, if you have an idea of what you are doing. Hell, even if you don't, it might be worth it for the education. Trial and error is by far the best teacher. I've killed my share of components in the past, but I consider the experience gained worth the cost.

[muddyfox470]

Ive never gone mental with my overclocks, just what I need or what I can see as suitable.

I bought an early Venice 3000+ (when they were all the rave) stock speed is 1800Mhz I overclocked it to 2520 (close to a stock FX55) BUT I undervolted the chip and it is still running sweet as nearly 1.5 years later. The chip has very low temps and hasn't come up with an error. I could push it a lot further but I don't need it plus any extra increase in speed will give me a negligible impact on actual ingame speed / benchmarks.

I don't know why but I have always seemed to believe GPUs are much more overclockable, but thats just my misconception. I have got a new 7900GS and the core is raised by 100Mhz so it beats a 7900GT - saved a fair bit of money in the process

Thats why I overclock to save the bit of money by buying the lesser hardware and overclocking it

I am extremely happy with my experience (I guess I have probably been a bit more lax in comparison to others) but it has saved me a lot of money, and I am getting good results with it. I often wonder about going up to dual core, but with my current system I am more than happy enough

Ian

PS. Just make sure your hardware can cope with the overclocking like others have mentioned, PSU, Motherboard and possibly RAM; although you can run dividers so RAM runs at 'normal' speeds whilst the rest of the system is overclocked

@ Oralpain you practically have exactly the same specs as me, albeit further overclocked, I would be interested in some of your benchmark results if you can be bothered I am getting 8220 (3dmark05) with the above spec > using the stock heatsink on the 7900GS and an evo33 on the cpu.

[coco]

i've always overclocked coz you get more bang for your buck, and anyway it is fun to see how far you can go. Aslong as you don't use crazy voltages your fine
and so what if you take a few months of the life of a cpu/gpu coz it'll still be going strong well after you've got rid of it on ebay etc

[doddsy]

Overclocking is very worth it. There are a few ways to look at it; firstly you can be buying cheaper components and having them run like more expensive ones ( like some of the other guys here) and secondly there are those who enjoy tweaking their systems to get the best out of it.

I like to think I'm a bit of both, being a student I have to watch what I spend my money on and that means I have to go for the cheaper options when it comes to components. Overclocking means I don't need to then have worse performance.

Like a couple of folk above I have an a64 3000+, I have mine running at 2.4Ghz which is fast enough to do most things, and it's running at less than stock voltages, 1.3v. My 7900gt runs quite happily at 550/1600 and in combination I am able to play every game I own at 1280x1024 at full details where as I would need to turn some things down if I hadn't overclocked.

[pollaxe]

I've done a bit in the past but don't tend to bother these days being too old and too lazy! I would do it when a system is getting towards the end of its useful life and if I've bought cheap and cheerful components I don't really care about but most of the time I found the hassle vs performance benefit ratio to be too steep to bother with.. YMMV of course.

[oralpain]

@ Oralpain you practically have exactly the same specs as me, albeit further overclocked, I would be interested in some of your benchmark results if you can be bothered I am getting 8220 (3dmark05) with the above spec > using the stock heatsink on the 7900GS and an evo33 on the cpu.

Only 3dMarks I have scres for at current clocks are 2k1 and 2k6. I get around 30700 in the former (less than a 1k increase over my x800pro, it's very cpu limited at this point) and around 5230 in 3dmark 2006.

Best programs I have found for testing are ShaderMark v2.1 and 3dmark 2006, game test 3 (the one with the airship).

Nothing draws more power/makes more heat than shadermark set to 1600x1200 4x AA (for 256 meg cards). At that setting it uses all of the card's video memory, without spilling over into system memory and getting bottlenecked. This gets my card a full 5-6C hotter than anything else.

The airship test in 3dmark 2006 is the most all-round demanding one. It is most prone to create errors that cause the drivers to throttle the card down. I use rivatuner's hardware monitor to log clock speeds (in addition to watching the framerate of the test) to see if the core speed drops at any point (other than the split second when switching tests). If it does, the clocks are too high.