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overclocking for n00bs?

minor threatminor threat Registered User regular
edited December 2006 in Help / Advice Forum
so i've been doing some investigating about my videocard and have determined that i'm definitely not getting everything i could be out of it. i have an nvidia geforce 7600gs+ w/ 512mb ddr2 ram. i installed rivatuner and it tells me the core is currently running at 400mhz and the ram at 266mhz. what do you think i could safely OC it to? how do i go about doing this? is it as simple as moving the sliders to where i think they should be? do i need to adjust the fans?

also, what are the dangers of OCing? i mean, the obvious one is burning out the chip which i'm not going to do. i don't want to do any major OCing, just enough that i'm getting better performance without having to upgrade.

i'll add that this is just for practical reasons. i'd like to get a bit better performance out of games, but not push my system to the limits. if i could even get an extra 10 FPS or so out of this i'd be thrilled :)

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    Locust76Locust76 Registered User regular
    edited December 2006
    I think an additional 10fps is a bit of a lofty goal. I've overclocked my 7900GTX by 100mhz on the core and memory side and I didn't notice any major speed increases and did notice graphical corruption if I pushed it too hard. I saw maybe 2 or 3fps in uncrowded, simple scenes, and normal fps on normal scenes with lots of action.

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    robaalrobaal Registered User regular
    edited December 2006
    Supposedly the newest ATI Tool (the beta) supports nvidia cards.
    It's pretty neat because it has an artifact scanner built-in and can do what you normally would do (ie. gradually increase the clocks and scan for artifacts) for you. It can also save the overclock as a profile and turn it on only when it detects that you are running some 3D application.
    Very neat.

    If you want to do it yourself then, as I said - gradually increase one of the clocks (in, say, 5MHz steps) and run some GPU stress-test, like windowed 3DMark on a loop to see if you get rendering errors (usually white dots or some more obvious things). When you do start to get errors back off a step or two and that would be the max clock for whatever you were overclocking.
    Repeat the same with the other clock and you're done.

    If the card has temperature sensors and you get errors at a high temperature you could try improving the cooling of the card or the air circulation in the case, so that the hot air from the card is removed from the case.

    If you get errors at a low temperature you could try some volt-mods, which might be possible by changing the BIOS on the card but that's a bit more advanced - there's a possibility that the card won't work with the new BIOS in which case you'd have to re-flash it with some other one (or the old one) but it's a bit hard to do when you don't get any picture; the solution is to get some cheap PCI card and use that to boot.

    You could also always force the voltage to a higher value by soldering some... thing to the card but that's a bit extreme.


    And the dangers? I suppose it's marginally possible that if you overdo it the artifacts will stay regardless of the clock, but I think the worst thing you're likely to encounter in a system freeze.
    Long-term though it is likely that, even if you don't get any visible problems because of the overclock, some of the auxiliary chips/capacitors will burn out, so cooling the whole card is as important as the GPU/memory.

    I think an additional 10fps is a bit of a lofty goal. I've overclocked my 7900GTX by 100mhz on the core and memory side and I didn't notice any major speed increases and did notice graphical corruption if I pushed it too hard. I saw maybe 2 or 3fps in uncrowded, simple scenes, and normal fps on normal scenes with lots of action.
    Ironically, the hardware volt-modding article I linked shows exactly 10fps gain from a normal overclock of the GS.
    The memory on the OP's card is crap though so it might not go as high (percentage-wise).

    robaal on
    "Love is a snowmobile racing across the tundra when suddenly it flips over, pinning you underneath.
    At night, the ice weasels come."

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    minor threatminor threat Registered User regular
    edited December 2006
    alright. i downloaded that ATI tool and it appears to be working pretty well so i'll see if i can get some decent results with that.

    just for reference, i got the 10FPS idea from this. i know it's a different card manufacturer and slightly different model, but i figured if they could improve their performance, so could i. *shrug* it seemed worth a shot, at least.

    with regards to the cooling, at the moment i have the fan and heatsink that came with the GPU and two 80mm case fans, one on the side and one on the back. the slot in the back can go up to 120mm, so would you recommend that if i decide to keep the overclocking?

    also, why is the memory on the card crap? i'm really new to this whole thing and so i'm not entirely sure what determines good and bad. i have an idea, but i'm hardly a pro.

    and what are, in your alls opinions, normal and safe operating temps? when i let this ATI tool run, it edges it up past 65C and that just terrifies me. perhaps it's because i don't know how hot things can safely get in a computer, but numbers that high are scary. at least for my noobish self.

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    EdgieEdgie TampaRegistered User regular
    edited December 2006
    Don't know the answers to your other questions, but 65C isn't a big deal. Before a card would completely melt its own face off, you'd see numerous graphical glitches, and it's likely your system would freeze. That said, don't go cranking everything up as high as possible to see if you can get your video card to melt. :)

    Edgie on
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    robaalrobaal Registered User regular
    edited December 2006
    with regards to the cooling, at the moment i have the fan and heatsink that came with the GPU and two 80mm case fans, one on the side and one on the back. the slot in the back can go up to 120mm, so would you recommend that if i decide to keep the overclocking?
    I suggest you first tidy up all the cables in the case, so that they are as much out of the way of airflow as possible - routing them along the walls is pretty effective.
    A bigger case fan wouldn't hurt but it might not be necessary. If the case/CPU temperature increases noticeably after stressing only the GPU then it might be helpful.

    If you decide to change the GPU cooling then there's an Evercool heatsink that uses heatpipes that's supposed to be efficient and is rather inexpensive. Also quiet.

    also, why is the memory on the card crap? i'm really new to this whole thing and so i'm not entirely sure what determines good and bad. i have an idea, but i'm hardly a pro.
    I guess I'm a bit prejudiced about this type of card, where the manufacturer equips it with larger amount of slower memory than standard.
    It might actually be the other way around - GDDR2 isn't new so maybe it's mature enough so that even the chips rated that low can work at much higher clock speeds.
    OTOH when overclocking system RAM you usually get better results with smaller amounts of it, so maybe the higher density will hold it back

    You can check the rated speed of memory by checking the print on the chips; memory chip manufacturers usually provide some .pdf that would let you decode it but often you can tell by just looking at the last 2 numbers - they represent the access time of the chip, in tenths of a nanosecond (so 20 would mean 2ns); the maximum frequency in MHz is 1000/<access time in ns> and then, as it's Double Data Rate memory, you multiply the outcome by 2.
    The point of this is that some manufacturers use faster memory, keeping the clocks at defaults, to appeal to overclockers or perhaps by mistake, I don't know.


    and what are, in your alls opinions, normal and safe operating temps? when i let this ATI tool run, it edges it up past 65C and that just terrifies me. perhaps it's because i don't know how hot things can safely get in a computer, but numbers that high are scary. at least for my noobish self.

    New GPUs can work even at 100°C without problems. ATI Tool's cube gets my X850XT PE up to 73°C and that's with good ventilation, before it would get into the high 90s, so IMO <90°C is OK if it doesn't cause artifacts.

    btw. that test is more stressful than games, in my experience

    robaal on
    "Love is a snowmobile racing across the tundra when suddenly it flips over, pinning you underneath.
    At night, the ice weasels come."

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    minor threatminor threat Registered User regular
    edited December 2006
    is the case temperature monitor you get with nvidia's ntune tool at all reliable? my case (nzxt trinity) has a case temperature read out on the front, but i find that it's not accurate in the least. it generally tells me the temp is between 25C and 29C but ntune or rivatuner tell me it's closer to 37C.

    i'll look into finding out the speed of the memory, although i may just not mess with that. using ATI Tool, i tried the "find max memory" function and with a baseline of 166mhz, i got huge friggin' artifacts around 190mhz. the core, however, went from 400mhz to over 500 with no issues. would it be worth it to overclock the core by 100 or so mhz (assuming it doesn't overheat) and not up the ram by as much?

    also, i'm looking at the specs and they say that the ram is clocked at 800mhz. so why am i seeing it at 166mhz in ati tool and rivatune? is this just me misunderstanding how it works?

    robaal, you sir, deserve some kind of medal. you're so helpful :) thank you.

    minor threat on
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