Overclocked AGP Speed?

DriveEuro

So your AGP card runs at half the RAM speed (133 = 66). So if I overclock my RAM what is the maximum safe speed to over clock my AGP slot to? I also heard that it severely will induce heating up your video card. I hear that clock rates on the AGP slot above 72 are excessive. Any help would be appreciated.

Erroneus

Well in many bios's there is a divider, so you can divide it to 1/3 or 2/5 fo your fsb, and in some p4 motherboards and the latest nforce 2 abit board you can lock the agp speed!!


But if go above 66, it will stess your gfx card, but normally it will become unstable when you hit the limit for that card....and not just incinirate (typo???)

RIV@NVX

I heard that even AGP can go over 66, PCI must be 33. Some PCI cards are VERY sensitive to OC-ing (Audigy, some controllers).
Either use good divider or even locked speeds, or better OC using multiplier (unlock).

skastel

My 8500 worked like a charm under 145FSB, ~72MHz for the card.
In fact I had two cards work great on that setup, so don't be hesitant to push it, besides, you're prob going to OC it pretty far before you toast anything. Lord knows my rig should still be in flames from some of the OC's I tried.

DriveEuro

See here's my problem. ASUS A7V133, this board does not have a function to change the AGP or PCI divider. When I go to setup my FSB in the bios on the right hand of the screen it says that the PCI divider will be set to 1/4 of the bus speed (when bus speed (RAM) is set over 120mhz). No where in my bios does it have an AGP divider......I'm guess my mobo is AGP clock speed locked.

Kelsenellenelvian

Have you checked for a bios update?

skastel

Yup, I just got an EPoX 8ka3+ cause I wanted total control of my rig, and I got just that. Asus makes stable, I mean rock solid boards(IMHO), Unfortunately stable isn't the name of the OCing game My A7V266-E was a great board, always stable and what not, but I couldn't OC very far at all. Such is life my friend. But I'm sure you can get a few extra MHz out of it if you try.

DriveEuro

i'm running the most recent bios, 1009.

DriveEuro

So question.........Will i even see results that are worth the overclocking of the agp slot? i read that you do not gain any results......by the way.......would agp 8x show a difference on my card versus my 4x?

JAV

DE,

At the stock FSB of 133 you're running 33.3mhz PCI & 66.6mhz AGP. If your bios doesn't have a divider change for the AGP, but it does for the PCI > then either the AGP is always 66.6 or it is always 1/2 of FSB.

Since the PCI will be 1/4 @ 120+ FSB & PCI *usually* 'gives out' (~36.6mhz) before AGP > it is doubtful to me that w/o locking the PCI (which you evidently can't) you're going to be limited to ~73.2 AGP no matter what. That equates to 146.4FSB.

If the AGP is locked @ 66.6 but you can get ~145fsb > that won't make the transfer of the data faster from RAM to the vid card, but it WILL make transfer of the data from the CPU to the RAM faster & the CPU itself will work faster. That will be a benefit in & of itself.

8x AGP isn't proving to be significantly faster, yet. It'll need programing & some other things (533+ DDRII) to start showing it's true potential, IMO.

HTH,

reno

AGP is set based on your FRONT SIDE BUS. Not your ram, whoever told you that gave you bad info.

Be careful, if your AGP gets overclocked, most likely your PCI is being OCed to, and your IDE harddrives ALSO get overclocked...which is not good for poor harddrives.

DriveEuro

I know it's not RAM i just accidently typed it in.....But for me, it is my ram speed, cuz my ram isn't DDR and secondly I'm running ram at 140 (testing 160 also). So for me it is my ram also.....By the way, what damage could overclocked PCI do for my hard drives?

DriveEuro

When I do sucessfully get a stable clock speed for the AGP slot, unless I already do......Will I see any decent improvements in how my card runs?

Because I am currently running pc133 at 136 fsb and dram speed.(so far 136x10, and agp 68mhz (vid card:295/600) yields better results than 140x10 and vid card 290/560.

Sandra Professional tells me that my current clock speed on the AGP slot is 68mhz........(136 fsb)......On my ti4200 64mb i basically hit my limit now on overclocking, 295/615, I can't really get any higher and be stable..........So once i significantly overclock the AGP slot will I see more positive results, or will i just be doing more long term damage to the AGP slot and/or card?

DriveEuro

Well it is definite that running higher FSB definetly lets me get higher 3DMark scores.....Running 133 FSB was the worst, 136 was actually rather phenomenal.....140 was great, so i guess i figured most of this out on my own........

reno

I've never been able to see any true benefits coming from AGP overclocking, and your harddrives run at PCI speeds, so if your PCI is clocked at 42mhz, your HDs are running at 42mhz, which will net you no gains and may cause instability (over 118mhz FSB on my machine ends up in corrupt files being read...bad crap)

JavaFox

Right now I'm running at a 360MHz (180DDR) FSB on a KT266A board. O.o

JAV

JavaFox,

So you have the PCI set @ 1/5 in BIOS? 180 / 5 = 36mhz. What is the AGP? > 1/3 or 60mhz? 2/5 or 72mhz? Not 1/2 & 90mhz ??? 90mhz would be a tad hard to believe, I've heard of some cards going to 84mhz. (not saying it ain't so, just ) What card ya got, btw?


Reno,

Seems @ 118 you're @ 1/3 & 39.3mhz PCI & @ 2/3 & 78.6mhz AGP. ??? Yes, no, maybe so?


DE,
@ 140 you're @ 1/4 & 35mhz PCI & @ 1/2 & 70mhz AGP. Both lower than JF & Reno & lower than the 36.3 & 72.6 I mentioned as 'limits' in my post. Seems you should be ok if your components stay cool & are good quality. You might consider a hsf on the mobo chipset (NB) to help keep it cool, if it doesn't have one.


Have a good one all & lemme know if I got the #'s right, plz.

JavaFox

Well, the thing is, I've never had a BIOS that allowed me to select my PCI divider. But I did not that I am running KT266A, which, to my knowledge, doesn't support the 1/5 divider. That would place my PCI at an astounding 45MHz. Any utilities out there to tell you your PCI and AGP clock?

I've heard bizarre claims --on more than one occasion-- of people running 100MHz AGP buses. I don't know if that's true, but is pretty insane.

I've got a R8.5KLE (128MB).

JAV

JavaFox,

SiSoftware Sandra in "Mainboard Information" has PCI > PCI bus(es). It states: version, # of bus(es), lists each bus & it's bit size & speed (xxmhz) & the multiplier. I'm presently running 109FSB & it lists my PCI @ "32-bit PCI (36mhz)" [it is actually 36.3] & multiplier > "1/3x". I don't have an AGP 'slot' so there is no info for me on that, but I imagine if SiSandra detected one it *would* be listed.

HTH,

Starscream

I ran a 100mhz agp for a long time. Good ole 440bx doesn't support a 1/2 agp divider so when I was running a p3 500 @ 750 I had 100mhz agp. I'm still on the same motherboard but these days I'm running a tualatin celeron with a 124 mhz fsb, 83mhz agp is still pretty decent I guess. heh.

DriveEuro

My mobo comes with a fan already on the chipset

DriveEuro

Well I've run my computer at a FSB from 133 -143.......Results for me say that I get the best results when running RAM at 133 (stock speed) with aggressive timings....143mhz (2-2-2). I guess maybe my ram isn't stable.....But i noticed when i overclocked the fsb over 137 mhz all my 3dMark scores went down significantly, like from 8904 to 8100 in one instance....Average drop of 3dMark was about 400. Maybe it's just that my ram doesn't run stable that fast, even with different timings.....Sometimes when Windows booted on a high fsb (over 137) it couldn't overclock my card ....... an error window would pop up saying basically it couldn't change the clock speeds.....weird eh?........

Well nonetheless, these results are only pertinent to my computer, but I just find it odd that overclocking the FSB has that much of an effect on my agp slot (the fastest the agp slot ran was 71mhz.....and that brought crappy 3dmark scores...). Neverthelss, I haven't had success with overclocking the FSB and getting decent 3dMark scores.....Some of you try dropping your FSB and see if you get results similar to mine.....Out.

Desert_Siege

My PCI bus is running at 41Mhz and AGP is 83Mhz. Been running that way for a year and on 2 different boards (Epox 8k7a+ and KT3 Ultra2R). Lowering my FSB decreases performance, but I am guessing the difference there is that I can run 166FSB with agrresive memory timings (2-2-2 1T Ultra) and your running in to problems at higher FSB with the aggresive timings if I read right, sorry if I didn't. I would say if your score is decreasing as FSB increases, another component in your system is crapping out on the PCI bus or your memory can't take it. I haven't seen many Nvidia cards that couldn't handle an AGP bus up to 75Mhz and most will run ok to the mid 80's, some even higher. I have GOT to find out why my board is not switching dividers when I increase FSB to 166 or higher. THere is no setting for it in BIOS and I was told it would switch automatically at 166, but finding this not to be the case, but thats my problem. Have you tried it with all the other cards out of your system?

DriveEuro

Well, I settled on 133 FSB (pc133 ram)...It runs the best and is rock stable with agressive timings, 2-2-2...Well nonetheless, I gave up on testing after a while, I don't have patience.

Murdock

You analyse this this isue very good ,when U overclock the FSB the HardDisks can be damaged
lets flow the air over the HD's with a big 120 mm blowhole,if not after a little time the hd gets overheated and can create bad sectors with hd's UP to 60GB and more