ATI 3850/3870 Voltmod thread

[Clint]

trying upping your memory frequency should improve your score greatly.

Well, if the card is hardmodded and the core is @ 1GHz it should be quite obvious that the memory is maxed out as well.

[-DC-]

hello, guys... still no info about asus EAH3870 vmod?(

[Random Murderer]

hello, guys... still no info about asus EAH3870 vmod?(

from what i can gather, it's impossible to volt mod an asus card until they leak the pinouts of their proprietary ic's. sorry.

[cka3o4nuk]

people pls help 3870 ddr3 powercolor.
didnt se no pcb like that on the topic. cand find vmod.

[tomcug12]

Is there an unlocked BIOS for the Gigabyte Radeon HD 3850 512 MB with Hynix 1.4ns memory chips?

[Clint]

Is there an unlocked BIOS for the Gigabyte Radeon HD 3850 512 MB with Hynix 1.4ns memory chips?

I'm using this:
http://www.techpowerup.com/vgabios/3...12.071128.html

It is for 1.1ns Hynix mems, but it works perfectly fine.

The 1.1ns and 1.4ns Hynix is the same chip, only that 1.1ns is fed with 2.0v and 1.4ns with 1.8v.
You might even gain a few MHz due to the looser timings on 1.1ns chips.

EDIT: I just remembered I did edit the bios to lower the memoryclock before I flashed my card with it.

[quake6]

Little OT,but can I use 3870 x2 + 2*3870?

[tomcug12]

people pls help 3870 ddr3 powercolor.
didnt se no pcb like that on the topic. cand find vmod.

cka3o4nuk, measure the resistance of marked resistor. According to Demolitionman1, it should be around 5.12 KOhms.

[LyP0]

ASUS EAH 3850 TOP on air, vgpu 1.62v vddr stock :

Dont you think that's a bit high for air ? I mean stock is 1.15 with that you can oc the card a lot. If you feed it 1.25 or 1.3v you could manage 1ghz core.
This is insane ( no offence )
If im benching my card on ln2 i'm afraid of going over 1.5vcore and you do this @ air ?

altough i must say i had an screw up when i vmodded my card. Set the vr to the lowest resistance available instead of the highest. I got a litte over 2.2vgpu, instantly turned of the pc, cut the wire... rebooted and the card worked fine ( still running on it ) i guess they are realy well built ( or i'm just lucky )

owh my max on stock cooler is 1020/1000 ( aftermarket cooler = 1080/1075 )

[rmjohnson144]

I bought a pair of Sapphire HD3870 GDDR4 #100225L

http://www.newegg.com/Product/Produc...82E16814102719

I also bought a pair of EK Waterblocks for it as well. they were on sale for under $50 each at NCIXUS.COM actually they're still on sale

http://www.ncixus.com/products/27163...ater%20Blocks/

The nickle plated are an extra $5.

anyway, I find this card has the same design as the one in the first post except mine is a blue board and not red, plus the IC has a slightly different part #. The red one is a uP6201AQ while my blue ones have a newer revision of uP6201BQ.



I hijacked this picture from Ertu as it is exactly like mine.


I was wondering if there is any major differences in these two chips before I start soldering. I have already ordered all the VR for this already as I just got registration verification yesterday to post. only took a week. lol

My parts won't be here until sometime next week. so hopefully I'll have everything straightened out by then.

My Parts list for vmod & vdimmmod:
4 81-PV37Y203C01B00 4 1.610 6.44
Murata Multi-Turn Po
20Kohms

4 72-T18-500 4 1.210 4.84
Vishay/Sfernice Mult
3/4" H/ADJ 500

4 81-PV37W504C01B00 4 1.610 6.44
Murata Multi-Turn Po
500Kohms
The list includes parts for the 8800GT vmod as well.

Thanks for any help/advice.
-=Mark=-

[rmjohnson144]

well, I got my parts the other day and tore my computer apart this weekend to install my water system, yesterday I went down and bought a soldering iron and a few more watercooling fittings and clamps. I got home and starting disassembling my video card to put on the water blobk and setup for some soldering and after looking very carefully at the video card it seems rather tiny. I'm not sure if I'm brave enough to do this soldering after all - lol

anyway, I was thinking of trying this pencil mod first and see how it goes. Does anyone know the resistance needed for the pencil mod, I don't remeber seeing it listed or not as I was planning on soldering. I plan on 1.4v - 1.5v or so.

-=Mark=-

[Eldonko]

Not sure if the p6201aq would be the same as p6201bq, cant find any info on p6201bq... Likely just a new revision, but I can't say for sure.

[JMKS]

Not sure if the p6201aq would be the same as p6201bq, cant find any info on p6201bq... Likely just a new revision, but I can't say for sure.

I think it is only a problem while we ignore the 4850 mods. Because it is the exact same IC [and layout] as used in 4850. So... if Asus is one step forward or one step back?

front


back


and comparision [the second picture, with text, is copied from #1 post in 4850/4870 voltmod thread; my picture is rescaled to match that 4850 in proportions ]




The mod should be the same, right?

edit: VGPU readpoint:

[Eldonko]

Cant see why it wouldnt be.

[Nosfer@tu]

I need to coil mods shamino once posted.

Been trough all 28 pages now and no link

Vcore, Vmem, OVP and Cap mod just dosent do it for me

I WANT MORE

[Riska]

http://www.xtremesystems.org/forums/...t=3870+1200mhz
Here you go mate

[Eldonko]

Yah, that is where the OCP mod came from and it works perfectly.

[JMKS]

The mod from post #813 (Asus EAH3850 with Glaciator heatsink) is working, successfully upped V with just pencil .
The problem is - the famous ~862MHz core limit . I reached it with ~1,38V [pretty stable I think] and then it is crashing, no matter how high the voltage is.

Is it safe to flash that card (pictures a couple posts before) with some non-Asus 3850 BIOS? If so, what 3850 BIOS is unlocked?
If it is not possible [flashing with some reference-like BIOS on that Asus card {I must add that the BIOS editor for changing V and clocks is working without problems, so the BIOS is for sure like the others, but I don't know everything about it}], maybe there is a way to unlock it by manually {?} editing original BIOS?

[fng77]

I´m thinking about getting myself 3x3850 or 3870:s and voltmod em to around 1 Ghz, I probobly will need a small powerplant to power them, but I love the idea to have three gpu:s on my Maximus, since I have 16x + 8x + 8x.

We got very good deals on Gecubes cards here right now:

3870 gddr3, 850 core, 1950 mem for 130 USD

3850 gddr3, 720 core, 1900 men for 100 USD

Cool or stupid? I dont care.

Its been a dream for quite a while now, and now the prices are beginng to settle at a nice level.

Well, I´m gonna start out with two cards, but that third pci-e x8 gonna look very empty and very inviting

[Vatos_locos]

you should better get 3 x 4850 they should be faster :p

[fng77]

I wish I could....

[crio]

Hi everyone...
I tried modding my sapphire 3850 256mb but didn't get any results.I used this mod but nomatter how much pencil i used the ohms stuck at 5.12.
What should i do?I am a little lost....!!!
Any complete guide on how to brake the wall of 770 core speed and 970 mem speed?
Thnks anyway.

[JMKS]

You probably need softer pencil. I have 5B, even if "everyone" recomends 2B. With 5B modding something with ~500Ohms is difficult [the absolute minimum I reached with 76GS which has ~540Ohm standard was ~320Ohm], but 5kOhm is absolutely pencil-moddable .

[crio]

2b/hb couldn't leave a mark on it.I mean it is gloss at that place and it is imposible to write.5b can make the difference?????

[GenTarkin]

question about my sapphire 3850 pencil mod..

I was able to drop R1222 down far enough to allow 1.43vgpu...

But weird thing is, my core is just not stable past 837mhz even at that vgpu.
I have AC Accelero S1 on it with the fans....it stays cool...
I have the correct bios installed on it thats not locked @ 862mhz..

Is the core I got just a really weak one?

Only thing I can think is, I dont believe I have any heatsinks on the mosfet section of the board where that group of 4x4 mosfets...
Could those be overheating and causing the low clocks?
hrm....