ATI 4850/4870 voltmod thread

[NBF]

I found the data sheet for these particular qimonda chips (HYB18H51232BF-10), but I don't really understand what I'm looking at :/
http://www.qimonda.com/download.jsp?...rev130_www.pdf

Perhaps someone else can take a look at that and let us know the max rated voltage?

Recomended max. voltage is 2,1V, the absolute max. is 2,5V, exceeding that may cause irreversible damage.

That's on chapter 4 of the datasheet.

Personally I wouldn't mind goind for 2,2V, maybe 2,3V with good cooling, but wouldn't try more than that.


Edit: Too slow, this is already posted, I think there's a lot of people readind this thread

[Clemmaster]

Where does it say recommended is 2.1v? For them, the operating conditions should always be under 1.9v, so that's a confortable value for them, no dead chip.

Nevermind I wasn't looking at the right pdf

[gurusan]

Thanks for all the clarification. I noticed it also said keeping them under 85c is a good idea

[adpr_02]

Is it okay if I solder a 50ohm vr if I set it at 100ohms?

If it is, will it have a different effect on my videocard?

[gurusan]

Sorry, can someone confirm which is the correct vGDDR read point?

[Boogerlad]

OK...I'm impatient. I stuck the probes in there (man this card is hot!), and my guess was correct. The points below show up as 2.01v on the DMM, so I'm pretty sure they are the measure points for the GDDR. Someone correct my drawing if anything is incorrect, please.



Pic courtesy of Techpowerup


Also, I want to rig the fan to run 100%. Are the red and black fan lead wires the positive and GND? I'm pretty sure they should be, but I don't want to fry the fan. Yellow for sensor, and blue for PWM?

read this post! any green spot to ground.

[gurusan]

^thanks.

dunno how i missed that.

[adpr_02]

Just wired up my card. I've got everything hooked up except for the VGPU test point. Anybody know where that is? I went over the thread 2x and couldn't find it.

[jimmyz]

Just wired up my card. I've got everything hooked up except for the VGPU test point. Anybody know where that is? I went over the thread 2x and couldn't find it.

in this pic the top of the picture you will see a resistor near the number c646 use the side of the resistor that is towards the power plug end of the card. sorry we didn't include it in the original info. it was the same as the 3850 so I assumed most people knew where to check , sorry. if you need any more info ask away.



http://www.xtremesystems.org/forums/...4&postcount=52

[Moty]

Hi, will my current Titan twin turbo: http://www.titan-cd.com/eng/vga/ttc_csc88tz.htm
fit on 4850?

and will those heatsinks:
http://pcb.se/ItemInfo?itemId=795607...A+RAM+Heatsink
cover all the power managment fo it?


P.S. how much dou you think core can be clocked up with zalman vnf-1000 level air cooler and only pencil voltmods?

[jimmyz]

Hi, will my current Titan twin turbo: http://www.titan-cd.com/eng/vga/ttc_csc88tz.htm
fit on 4850?

and will those heatsinks:
http://pcb.se/ItemInfo?itemId=795607...A+RAM+Heatsink
cover all the power managment fo it?

I would have to say no. on the twin turbo, the list doesn't include the x1900xt or the HD2900 or the HD3800 which all had the same mounting pattern as the 4850. if it will fit the cards I mention it will work if not than no guarantee. but if you know anyone who is handy they could mod it to fit I imagine.

the ramsinks are fairly universal it all depends on what you are cooling it with .

[adpr_02]

in this pic the top of the picture you will see a resistor near the number c646 use the side of the resistor that is towards the power plug end of the card. sorry we didn't include it in the original info. it was the same as the 3850 so I assumed most people knew where to check , sorry. if you need any more info ask away.



http://www.xtremesystems.org/forums/...4&postcount=52

Hey, thanks a lot. I'll get that hooked up and hopefully do some benches soon. Can't wait for that D-TEK gfx block...

[Moty]

I would have to say no. on the twin turbo, the list doesn't include the x1900xt or the HD2900 or the HD3800 which all had the same mounting pattern as the 4850.

There's what it's capable for:

ATI
RADEON X1600 / X1800 / X1900 series

(i use it with x1800gto for now)

As i know hd2900 have core protection metall pad that is higer than core itself and that was the reason that there was many coolers which had no contact with core, so they cannot be used.


I will try to find information about mounting holes of 4850... hmm where to start...

[jimmyz]

There's what it's capable for:





As i know hd2900 have core protection metall pad that is higer than core itself and that was the reason that there was many coolers which had no contact with core, so they cannot be used.


I will try to find information about mounting holes of 4850... hmm where to start...

OOPs i think I missed that at the site. the hole spread is 2.1 inches center to center. which is 53.34 mm approx.

[Moty]

OOPs i think I missed that at the site. the hole spread is 2.1 inches center to center. which is 53.34 mm approx.

that's 100% precise measurements?

[jimmyz]

that's 100% precise measurements?

is this precise enough for you?



I wouldn't tell you something if I wasn't sure. since my calipers are in sae. I am assuming the metric would be rounded down to 53mm

[Specialfighter]

can somebody show us the exact points for solder the potis ?

discribed for idiots ?

that will be nice

[Moty]

is this precise enough for you?

Well thanks 4 the photo, but can you measure @ 45 degrees?



@-----------0
--------------
--------------
--------------
--------------
--------------
0-----------@



i need distance from @ to @, thank you.

[jimmyz]

Well thanks 4 the photo, but can you measure @ 45 degrees?



@-----------0
--------------
--------------
--------------
--------------
--------------
0-----------@



i need distance from @ to @, thank you.

2.965 inches which is approx 75mm (75.33) without the other items needed like guage pins that is as accurate as I can get.



here is a diagram for Specialfighter and anyone else who wants it.

[IMG][/IMG]

[Moty]

2.965 inches which is approx 75mm (75.33) without the other items needed like guage pins that is as accurate as I can get

Science Titan uses a diagonal measurments, My twin turbo wil fit on 4850 because it uses 75.4 mm mounting holes which is same for:
RADEON X1600 / X1800 / X1900 series
RADEON X1950 series
RADEON X2400 series / X2600 series


Thank you. I will now know that my cooler is good and that all with your help. I'ts 3.29 am at my time zone and i can now have stress-free sleep(i need to wake up at 6-x )

[GoldenTiger]

Any pencil for 4870 yet?

[Moty]

Is there any chance for softvlotmod at 4850 when oc tools get updated?

[W1zzard]

Is there any chance for softvlotmod at 4850 when oc tools get updated?

in like 4 steps and mostly downward. same goes for bios modding. if you want to have more voltage you must do the hardmod

[gurusan]

Just penciled to 1.18v idle 1.48v load

tested at 850/1100 so far and of course passed with flying colors. Am hoping to do over 900mhz on this voltage.

28c idle and 34c load

[rym]

whats the safe max v

??????


1.3 for stock with fan on high

1.3-1.4v tops for after market cooler/

water 1.41-1.6