Alienwhere Posted January 23, 2006 Posted January 23, 2006 subscribed, 7800gt in mail as we speak.. Will post results.. So disreguard first post and get the newer stuff or wut? Whats best way to do this? Share this post Link to post Share on other sites More sharing options...
zeimbo Posted January 23, 2006 Posted January 23, 2006 ive got the evga nx-517 7800gt CO as well, mine auto detected through nvtweak at 495/1.17, i put the asilencer 5 rev 3 on there and it now gets 500/1200 stable and then slightly artifacts 530/1220 so i turned it down a little. NO VOLT MODS OR ANYTHING. Share this post Link to post Share on other sites More sharing options...
Guest laydback Posted January 23, 2006 Posted January 23, 2006 Honestly I didn't benfit at all from the voltage mod, it wasn't until I added the +35 delta until I saw a performance boost. Keep in mind though you have to lower your core clock if your going to use a delta value. For example if you max clock is 500mhz for core, with a 35 delta youd want your core at 465 (465+35 = 500mhz). Share this post Link to post Share on other sites More sharing options...
Redbeaver Posted January 24, 2006 Posted January 24, 2006 so can anybody lay it out in layman terms whats delta? are u saying compare to what i got now, core 510, it actually gonna perform better at 480+delta30 for example? before the voltmod i too detect 490+/1.17, but a good rule of thumb from those as i live by is to downclock it abit, coz auto detect stress ur component for awhile only whereas games can really deal some damage after the mod, i clock it up to 510/1.2 stable. i dont wanna bump it up coz its pretty good so far im happy with it. maybe after i get the NV AC silencer then i'll increase. alienwhere, try using the soft voltmod first, then install coolbit, auto detect first, then observe the temp while running rthdribl at x16AA and max everything out. it will drop ur 7800GT to 20fps or so. if not, bump the resolution make sure ur 7800 is struggling on that test, then watch the temp. if everything cool, try raising the overclock....if artifacts shows/lockup/bsod, then drop the oc. if ur 101% sure that its all good, u can keep it running there using coolbit or rivatuner, or u can flash ur bios again using the overclocked one. remember! nbitor 2.6A does NOT require u to do the 6800series trick. just read teh bios then select the extended voltage. then just put it to 1.5V. done. Share this post Link to post Share on other sites More sharing options...
cdidhe Posted January 24, 2006 Posted January 24, 2006 Honestly I didn't benfit at all from the voltage mod are you sure u edited your volt table properly? first time i didnt and i saw no chagne as i flashed properly so i assumed the newbios was correct. check with a multi meter to see if you got 1.5v or still 1.45v. your delta will chagne regardless if you edited the v table correctly or not. You really should see a diffrence with this mod. :nod: :nod: :nod: Share this post Link to post Share on other sites More sharing options...
Redbeaver Posted January 26, 2006 Posted January 26, 2006 dunno if i should post here or not....... but lookat this guide for hardmod. http://www.vr-zone.com.sg/?i=2656&s=1 now the question is, which part EXACTLY where do u pencil for the memory vmod? i dont want to mod the vcore anymore, i can get it done with softmod bios, but its he memory that i wanna bump. looking at the tutorial, he draw a red "U" line across the resistor mentioned, basically shorting it. now i finished my comp-eng degree more than a year ago so im abit rusty... but if u connect those 2 ends with a low resistance medium (like, oh say a #2 pencil line?), wouldnt the current prefer the pencil line instead of the resistor??? if that is the case, then instead of having 620ohm through that resistor, current will go to the low-resistance pencil line, delivering some deadly amps??? the author said by doing this pencil trick will reduce the resistance from 620 to 600 ohm, thus generating slightly a larger voltage (0.06increase) ... which i dont think makes sense. yes lower resistance will generate higher voltage, but i think if there are 2 resistance in 2 lines, there wil be higher current passing the one with lower resistance and thus in the end there will be more voltage coz there are more current.... yes that is the whole idea, but we're talking about a 620ohm resistor vs a pencil line! which i believe has less than 100ohm per stroke. if u pull the old v=i.r rule, thatll generate a WHOLE lot mo than a 0.06V increase....... Now, i know that there are people out there that suceeded pencil-modding their vram, so i think there a possible answers to this mistery: lets do the math , lets calculate the resistance of the #2 pencil line, thus if u pull the parallel equation in there, i = v/ r = 2.08/620=3.3548mA. this wont change. in parallel, total i = i1+i2 (the pencil line and the resistor) where the ratio of i1:i2=r1:r2,and also where v=v1=v2. so if the increase is indeed 0.06, then v=v1=v2=2.14. Now r total would be v/i=2.14/3.3548mA=637ohm. see where im goin? that means an increase in voltage is an increase in the resistance! now how is shorting the resistance with the pencil line, INCREASE teh resistance???? i dont get it.... lets continue..... in parallel, 1/r=1/r1+1/r2, so 1/637=1/620+1/r2. where r1 is teh resistor and r2 is the pencil. that will ends up being......umm.....watever that is, r2 = NEGATIVE! that is IMPOSSIBLE. because theres no such thing as a negative resistance. so bottomline, u cant incrase the resistance (which is needed to increase the voltage), by putting the stock resistor (620ohm) in parallel with it!! Duh...anoter physic law, adding a parallel resistor will decrease the total resistance. not increase. that means, that picture on the link above where it draws the line going around the resistor is wrong..... OR (are u bored yet?lol) the author meant to said that the resistance is decreasing, but there's no sense to this as it would decrease the voltage as well which kinda beat the whole purpose... at this point we all know that the most basic electrical rule is voltage=current x resistance. so even at that the author is again wrong......... SUMMARY= the author said: - drawing a pencil line around the resistor (creating a parallel connection), will reduce the resistance. This is right according to the paralel rule. - thus with the reduced resistance, the voltage will increase. this is wrong!! so there are 2 posible explanations: - the drawing is wrong. he actually meant not to draw the pencil line AROUND the resistor, instead, ON the resistor (i dont know how to do this), thus it will (probably) theoritically add a serial (not parallel) resistance to the 620ohm, upping it to 637ohm, thus we got the 0.06V increase. - the drawing is right, it is a parallel resistance created by the pencil line, thus decreasing the resistance to 600ohm, however, that will also decrease the voltage! not increase it! so how the heck do people do it?? oh...my...god..... ive been writing this long a$$ post then i realized..... why YES, the resistance did decrease, thus the voltage IN THAT RESISTOR decreased, or should i say in the parallel circuit decreased, BUT perhaps the memory is somehow linked SERIAL with that circuit, thus since the total voltage doesnt change, and in series vtotal=v1+v2, so since v1 decreased, v2 increased!!! HOLY CRAP NOW IT MAKES SENSE!!!! i wrote the whole post overnight then i thought i'll sleep in first before i proofread it, and this mornign evrything seems so right! good u'll never know what a good night sleep can do to ya..... but still, there is the possibility that the drawing is somewhat inacurate or somethin so i still appreciate any inputs on this afterall, i dont wanna short the wrong line and toast a $400 card........... hope u guys understand, THANK YOU FOR READING!!!!!!!!!! Share this post Link to post Share on other sites More sharing options...
Guest Dynamic Posted January 26, 2006 Posted January 26, 2006 Here is a step by step instruction on how to do this process on your GT. http://www.planetamd64.com/lofiversion/index.php/t15247.html Share this post Link to post Share on other sites More sharing options...
Redbeaver Posted January 26, 2006 Posted January 26, 2006 Here is a step by step instruction on how to do this process on your GT. http://www.planetamd64.com/lofiversion/index.php/t15247.html thats a negative that link is for increasing the vcore through BIOS...and i did that. i know my link points to where u can do hardware mod on both vcore and vmem, but im just basically interested in the vmem and thats what my long post is all about memory... not vcore.... thx anyway Share this post Link to post Share on other sites More sharing options...
Redbeaver Posted January 26, 2006 Posted January 26, 2006 here's the 2nd part of my "investigation" lol sorry if im being a noisy little bastard, but i just wanna make sure y'know? Alrite, the other solution there in that guide is to solder a 10k ohm into the 620-ohm resistor. then start twisting down the variable resistor to reduce the 10k into something less, thus theoritically reduce the total resistor thus reducing the voltage there and increasing the memory voltage. but whats the initial value when i boot up the card? does it really increase the vmem when i reduce the 10k variable resistor(vr) ? Lets find out with 10k ohm being in parallel with the 620, i thought to myself since any resistance connected in parallel always reduce the total resistance, thats why the author pick a huge 10k ohm (compared to the 620 ohm that is). so lets how how much it fare at the default 10k value. 1/total R = 1/r1 + 1/r2. initially total r = r1 = 620. now we throw r2 (10k) into the equation, lets see how it goes... 1/r = 1/620 + 1/10,000 = 16.129/10,000 + 1/10,000 1/r = 17.129/10k r = 10k/17.129 = 583.8 !!! ok so we proof once again the theory that adding another parallel res will decrease the total res. but using the pencil trick we drop from 620 to 600... if 20ohm difference (620-600) gives u 0.06 increase, then 36.7 diff (620-583.8) will get u a 0.1101volt increase!! that means: with the 10k ohm trick compared to the pencil trick, ur Vmem will be 2.08+0.1101= 2.19 Volt MINIMUM!!!! the question now becomes, is 2.19V safe for the memory?? this only shows that the resistor trick will give out more vcore at the least, but more controlled variation, where the pencil trick will give you the ability to raise the volt slower! given u got steady hand that is....... on another note, of course, getting a larger resistor, like a 100k ohm will give u...umm......161.29/100k+1/100k=162.29/100k=100k/162.29=616.181ohm, and coming from 620, that will only increase the vmem by at most 0.01increase approx, so by default is ur using 100kohm instead of 10kohm, u'll get the minimum voltage much closer to the stock voltage. HOWEVER, the problem now become, how sensitive the variable resistor ?? because as u twist the control and getting lower voltage, the total resistance with the 620 will drop exponentially! as it getts closer to 10k, then to 620, the voltage will become much much sensitive! that = dangerous! so in the end... 10k is probably ur best bet.... given that 2.19V is not too high for the minimum voltage that is......................... anybody can comment this? Share this post Link to post Share on other sites More sharing options...
BioVader Posted January 27, 2006 Posted January 27, 2006 Anyhow I've vmodded 2 7800GT's and I've had no problems at all.. I used the guide found at vr-zone.com and used 2 10k Ohm VR's. My first card was able to run at 590/1270 stable and my second card is running at 630/1377 stable. The bios mod is useless unless you can't solder. Here is a link showing my mods on ocforums.com http://www.ocforums.com/showthread.php?t=425634 I will be updating my scores resulting from the second 7800GT soon. Right now I'm playing with both cards in SLI... Share this post Link to post Share on other sites More sharing options...
ripken204 Posted January 27, 2006 Posted January 27, 2006 my evga 517 with the mod! havent seen temps above 56C with my nvSilencer5rev3 Share this post Link to post Share on other sites More sharing options...
Redbeaver Posted January 27, 2006 Posted January 27, 2006 Anyhow I've vmodded 2 7800GT's and I've had no problems at all.. I used the guide found at vr-zone.com and used 2 10k Ohm VR's. My first card was able to run at 590/1270 stable and my second card is running at 630/1377 stable. The bios mod is useless unless you can't solder. Here is a link showing my mods on ocforums.com http://www.ocforums.com/showthread.php?t=425634 I will be updating my scores resulting from the second 7800GT soon. Right now I'm playing with both cards in SLI... very cool! thx BioVader! edit: AWESOME! now i need to go to the electronic shop to grab a few thin-wires and a couple of 10k VR's do u use the log VR or normal one? nice soldering too btw, i got 3 yrs of experience from my CompEng degree and yet not sure i can do that neat btw, Bio, just wanna make sure, the vmem mod, with 10k pot, its soldered across the resistor right? Vr-zone's pic is abit blurry, and the pic on ur first 7800GT looks like ur connecting too much to the left, goin over the other resistor left of it Share this post Link to post Share on other sites More sharing options...
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