Thanx for the info! :) Will pickup a new 200K trimmer this week. Crysis gives me artefacts at 1200MHz and 2.12v.
really want to try less voltage :P
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Will a 100 Ohm vRES do for the HD4870 vGPU mod? It's a 15 turn so I reckoned it should be fine.
if you have a stock 4850 heatsink thats intact i want it..
Randy
rym i have a spair 4850 sink..
also i could not resist i grabbed a 4870 as well. $274...:up::up::yepp::cool::p::D so now i need to find a nice 2x16x pcie mobo all i have is 16x 4x.
http://www.tigerdirect.com/applicati...1&sku=D10-4870
I have a volt mod on my 4870, but I have a strange problem. I can bench on 850/800, and on 650/1150, but when I clock both the memory and core, the max I am stable is 800/940. VDDC is 1.307v idle and 1.363v load. I think it's OCP ( over-current protection ), but I'm not certain that is the case.
First mod on this new card, fan now runs 100% from POST to shut-down, perfect for air benching. Now 3DMark06 stable on default VGPU @ 875/1175 (AMD GPU Clock Tool) & 900/1200 3DMark01. I plan to do some BIOS overclocking this weekend, I'll keep you posted on the results.
http://img.photobucket.com/albums/v3.../R770_ffan.jpg
http://img.photobucket.com/albums/v31/canny/20597.jpg
iam going to pick up some 10ohm resistors tommorrow for 4870vgpu mod, but im not to sure which one i need, this is what they sell;
http://www.maplin.co.uk/Module.aspx?...C=SO&U=strat15
What increase in voltage will this achieve? thanks in advance
To get 1.41v GPU, shade the resistor in the TPU article (the resistor, not the solder dots) to around 600 - 700, then modify the BIOS to get 1.263v at load (key in 1.263v under the clock settings), and... voila.
what resister to shade in tpu article for gpu ?a resister could be put in place instead right. Penciling is allowing more v thriugh the resister right.
remove the resister and what resister to put in its place ?
Penciling it means you are reducing its resistance. Anyway, first pencil mod here:
http://www.techpowerup.com/articles/...voltmods/151/2
my pics look just like the ones here (used pencil mods)
http://www.techpowerup.com/articles/...g/voltmods/151
i don't have any resistor or hard mods so no real point in putting pics of the card itself.
.6 resistance on the gpu resistor got me 1.41v load. 3.85 i believe on the memory resistor got me 2.07v load.
How much extra MHz are you boys getting out of the mem after vmodding? I'm up to 2300MHz effective and that's about as far as I can go and be stable. Worth modding the mem?
2x HD4850 is much more powerful than 1x HD4870, but the 4850s in a pair cost a bit more. HD4850s aren't actually better than HD4870s for overclocking though. I've yet to test my second card but the first one does 870/1235 Furmark stable, so it should do mosts benches at 900MHz core. Everything is stock, but the fan runs at 100%. I haven't seen an HD4850 that benches at 900MHz with only 1.265v vGPU (stock 4870 vGPU). I'm not even talking about the DDR4940 memory :D The RAM needs more volts though because the card performs equal or worse above DDR4700 than it does at DDR4700.
OK cool , do we have software yet that can clock these cards this high with CF enabled ? What are you guys using to clock so high ? (ie CCC only goes to 790 and the evga tool didnt support two clocked cards last time I tried).
Is there a pencil mod for 4870 ? Or solder mods only ?
:up:
I use AMD GPU Clock Tool 9.8. It should be floating around these forums somewhere but you can also just google it. For Crossfire I would recommend flashing the BIOS' of the cards to desired clocks if you want to go beyond the CCC limit. Overclocking cards in Crossfire could in theory work using the AMD Tool.
I tried AMD tool but it stuffs up with second card settings , it clocks one card but doesnt like the second .
Why does clocking from 750 to 770-790 seem to make no difference or even score less (with CCC) ? I dont think Im cpu limted that badly at 4400mhz .
Is it hard to flash the cards ?
:up:
You did select the 2nd device when you tried to OC the 2nd card?
You shouldn't be CPU limited in almost any games/settings worthwhile with a pair of those cards. Can you give me some numbers? Like Crysis at high settings or the like. It sounds odd that the cards perform worse at a higher GPU clock.Quote:
Why does clocking from 750 to 770-790 seem to make no difference or even score less (with CCC) ? I dont think Im cpu limted that badly at 4400mhz.
No, but honestly I don't really trust the RBE BIOS Editor to mod BIOS'. I do it manually in a HEX editor. Flashing is simple if you look up how to make a USB stick bootable and read a bit about the basic commands of the flashing program. You can flash cards in Windows I think, but I use DOS because it is considered safer. Just make sure you get the latest ATIFlash and check if the BIOS you are trying to flash is 128kb in size and not 64kb.Quote:
Is it hard to flash the cards ?
:up:
I'm having the same issue my memory goes up to 1200 with core at 750 but I can get my core up to 880 with memory at 750. but something like 860/1000 is completely unstable. I'm trying to do the memory volt mod to see if I can get some sort of stability but I'm not sure about the memory voltage reading for vddc I read 1.5 volts. I have 1.47 volts on the core now. Its wierd though I can get 880 core and 1150 memory artifact free in ati tool but drivers crash in 3dmark
i can have 885/1200 for crysis and furmark and 900/1200 for 3dmark 06,05,01 and 910/1200 for 03 with 1.45v, on air (accelero s1)