NVIDIA GTX 480 Insides + parts - Page 1
Forum section: electronics / general

author: BiOzZ
author_rank: Regular Contributor
timestamp: April 10, 2015, 06:06:36 pm
content: I had my nvidia GTX 480 die on me after some years ... interesting fault of the screen blanking but keyboard still responsive than sudden crash with no BSOD when its under heavy load (rendering or ARMA 3)Tried reflowing it with no dice so i broke down and got a 980but i have always been fascinated by complex equipment like this so i took it apart and traced things ... i really want to know what voltages it is running off but i can't get it to boot up without a computer so i guessed by the voltage limits of other parts and resistor configurations (and what i know)It looked exactly like thishttp://images.anandtech.com/reviews/video/NVIDIA/GTX480/480card.jpgbut with wankey little gigabyte stickers on iti am not sure (tho doubt it) if gigabyte rolled their own boards or if they used boards by nvidia and made their own case or if its just a rebranding of an nvidia parti put in the specs of a non-overclocked unit even tho i over clocked it at the time ... see specs herehttp://www.geforce.com/hardware/desktop-gpus/geforce-gtx-480/specifications(click to enlarge) (BLUE MEANS UNDER THE BOARD, RED MEANS VISIBLE)i did the best i could ... some of the parts were obscureexcuse my spellingwhy would this be interesting? well i always look at professionally designed and well tested products to understand how a well made product is madesome things to point out look how far away the fan controller is from the fan, and how far the main 6 phase buck converter is from the main driver stages (this can operate at 1mhz)also i did not know you could buy separate synchronous mosfet drivers!and 74 logic is alive and well!also all shunt resistors appear to be 1 ohm and there is one for each stage (if they are shunts)Also there is a fitted "E" labeled fuse or PTC on the underside of the non-fitted components behind the HDMI ... HDMI 5v power? im not sure there is no other obvious fuses on the thingThe 2 connectors on the top are just 12v inputs (they are required to run the thing)the DVIs are both dual link and one of the DVIs appear to have an unfitted displayport or HDMI connectors probably as a drop in replacement for the DVI in manuthe main GPU has no info on it, but i suspect it is either an atmel ATMEGA328 (running at 16mhz) or an intel i486 (running at 8mhz) (this was a joke)EDIT NOTE: i think 121uh inductor should just be 120uh ...EDIT 2: Those 4 pin connectors unfitted around the power side appear to connect to the SMBus and one via some sort of unfitted buffer or shifting chip

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 11, 2015, 09:19:44 am
content: Thoughts:- Core is probably 0.9 to 1.2V. Older GPUs may be higher than that, but I wouldn't think anything newish (5-10 years??) would be above 1.2V. That would definitely be the 6 phase converter.- Interesting, ULR is an Illinois Capacitor series. Also X-Con (whoever they are), which seems more likely. Both polymer aluminum types, though (coincidence or not?). And whoever/whatever the smaller, blue-print ones are (Nichicon..??), but definitely polymer in any case.- A little curious that they used gate driver chips, but that'll help keep the signal clean -- that much distance between controller and FETs is probably hopeless otherwise.- The chokes are almost certainly 0.12 or 1.2uH. They aren't 120uH, at least not if they're handling more than a few amps (which I would hope so). And, no, there isn't any marking standard for inductors, as far as what numerical or letter code means what value -- 121 could be nH, uH, I've even seen it for fractional uH (so that "121" would be 1.2uH). So, alas, nothing to feel bad about, their markings are but a suggestion...- The 1 ohm resistors, paired with nearby 0603 (0402??) ceramic caps, look to me like RC damping networks to alleviate ringing. This can be handy around high switching current (which, for as many layers as this board will use, is probably not a problem), or just to dampen EMI or ringing, for necessary interference reasons, or "just because".- There's a bit of a smudge near C106? That's not smoke residue, is it?- The dual phase is certainly for the RAM, agree. Looks like 0.33uH chokes, and more polymer caps. 1.8V is possible, though I'd suspect 1.5V is more common these days? The RAM datasheet would say, in any case.- The two 1117 regs are probably just for glue... powering the switching controllers (maybe?), IO interfaces, etc.?- The one switcher remaining, the NCP1579 and dual FET, might be... VCCIO? Might be 1.5-2.5V, not sure what PCIe (of whatever version) runs best at.- The SMBUS controller might be located there, just to be closer to the edge connector and stuff? Probably doesn't matter much. The connection to the fan, of course, only needs to be one PWM line or whatever, so it's no big deal to be all the way over here.- Not sure what the 74ACT is doing; it's fast and CMOS and TTL threshold, so, maybe some glue function related to the DVI connectors?- Interesting having that serial flash there. Could be firmware, could be hardware configuration -- who knows? Seems like it should be bigger, if it's hinting at BIOS functions or whatever. But I have no idea how much is hard coded into those GPUs, and how many little sections they have hidden inside -- do they do any FPGA fabric, but how would we know if it's undocumented or NDA'd? Do they have MCU cores in there, for basic management functions and setup?- I don't see any PHYs -- at least, that have been highlighted (maybe there are on the back side?). Wouldn't seem like a good idea to run HDMI or DVI directly out of such a dear piece of silicon!!Still other thoughts:- If you're thinking about an even more, ah, "in-depth" teardown...Heck, you could salvage the capacitors, inductors and MOSFETs (and switching controllers and drivers, if you like), of course you pretty much need a PCB to use them, and reflow soldering. You can pretty safely assume all the MLCCs are 25V or less, and about as big as fits into the respective sizes (so, ~10uF around Vcore, and maybe 1uF, or a bit less, for the few around the 12V stuff).- The layouts and routing beneath the bigger components might be interesting. Lots of balls under those RAMs and the GPU. Lots of fine traces, lots of length equalization, diff pairs, the works.- A cross-section of the board would be interesting. 8 layers? More? Taking slices near the connectors, edge contact, GPU/RAM, or power section, etc. might be interesting. Sand the edge smooth and photograph under good magnification (and with size reference!), if possible.- Completely and utterly reverse-engineering the poor thing would be rather over the top, but damn impressive. It would be neat to see all the vias (buried/blind/micro?) and lots of huge power pours inside the thing.- Maybe you can take it to your dentist and get an x-ray for free/cheap? Needless to say, a much easier option..Cheers!Tim

author: TiN
author_rank: Super Contributor
timestamp: April 11, 2015, 09:44:35 am
content: SPI Flash is videobios.Display interfaces run off GPU ASIC since long time ago, like GeForce 2/3 or so. Sometimes there is exception, like G200 GPUs (GTX280,285) which had no space on die, so display stuff was in separate NVIO ASIC. No buried/blind via stuff on mass-produced card like this, it's cheaped down reference design, every cent is saved. It's 8 layers PCB, every layer except middle ones are sandwiched between ground layer.Only card I remember seeing buried vias is Radeon 2900XT.Chokes are 120nH, pushing 25-35Amps thru each phase.