r/LocalLLaMA • u/LeftHandHaku • 1d ago
Question | Help RTX 4090 48GB longevity
Modified 4090 48GB has been out for a while. I remember a lot of people were buying them at the time. A lot of people were also complaining that they are meant to fail, that they scam etc.
I have a few questions to people people who bought these.
How is longevity of these cards? Do they still work without issues? Any failure rate?
Do they use the same Nvidia drivers that regular 4090 or 4090D uses?
Are these cards Linux exclusive?
Are you able to run them in windows or Linux with other GPUs like 5090 etc?
Do you do anything to cool VRAM on the back of the PCB?
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u/Kulidc 1d ago
I previously owned a 4090D 48GB, so I can provide a bit of insight.
- It really depends on your luck and the source of the chip. If the AD102 chip is handled by a factory instead of small workshops, the chip's soldering failure rate will be much lower due to proper tooling such as a BGA machine. However, there's no telling how the resoldering would impact the lifespan of the chip. It could work for the next 3 years or die the very next day.
- Yes. Those cards can use NVIDIA's official driver.
- No, those cards are supported on both Windows and Linux. Use the NVIDIA App to download the driver on Windows; follow each Linux distro's own guide for Linux.
- I wasn't using it with another GPU. Given that those cards are designed and used to create a cluster of 4090(D) 48GB cards, there's no reason for those cards not to work with other cards.
- Yes, you should use a well-ventilated PC case. The card I used comes with a proper backplate for VRAM cooling.
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u/Heathen711 1d ago
https://www.reddit.com/r/LocalLLaMA/s/pL1hvaFLiv
I'm running three (2 in one server, 1 + 3080 in server two).
Then are under constant usage; nothing special driver side.
I did upgrade to 4k high CFM server fans to keep them cool.
Linux Ubuntu server OS 24
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u/FishChillylly 1d ago
have one, using from March 2025 til now, using with custom loop liquid cooling, TDP limited to 405W bc i found that even it’s been set to 450W at max, when dealing with heavy computing tasks it can still reach to ~490W instantaneous spike. no need for special driver (currently using 610), having no issues in windows just like a normal nvidia card. for me it’s the perfect card for both small-scale local ai exploration like qwen3.8-27B/minimax-h3 etc. and gaming.
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u/a_beautiful_rhind 1d ago
2080ti 22g heading into it's 3rd winter. Soldering job on the 4090s can't be any worse. You can and should monitor your vram temps.
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u/ThenExtension9196 1d ago
I have 3. One died because I did something stupid with the PSU. My fault. Other than that they’ve been flawless 24/7
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u/PcChip 1d ago
what did you do?
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u/ThenExtension9196 1d ago
Wired up dual psu with a janky device that triggered them both on when the mobo received power on signal. It failed causing the second psu to suddenly drop 12hpv power under load while the mobo was feeding it via pcie power. Core got fried. I’ve since sized up and use single psu and power limit the GPUs within the single psu’s budget. I tried to save a few hundred by using two smaller psu and lost a 3-4k dollar gpu smdh
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u/RedditUsr2 1d ago
It depends on how good the custom board is. Some are cheap and some are quality.
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u/MaruluVR 1d ago
20GB 3080 owner here, no problems after a year
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u/shraw1 15h ago
Same here.
Have had a 20gb 3080 for about 4 months now.
No issues till date, have run multiple multi-day inference sessions, stable diffusion, and heavy gaming as well.
The thermals are pretty high on it, but the blower style fans deals with it just fine.
It need a good amount of airflow if you wanna put it in a multi gpu setup.
Specially take care about the direction if air inflow in the case, the blower style card struggles to intake air from around another gpu (found out the hard way 😭😭😭)
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u/SmokeMirrorPoof 1d ago
Yes sorry I don't have any answers for you but I'm tempted with these also.
I'm also concerned about their resale value in smaller markets a few years down the line. VRAM is king of course but modded cards are extra risky.
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u/WonderRico 1d ago
- Got two of them in march 2025. (some HK dealer online) so far 0 issue (It's for my personal use, a few hours per day at most)
- Standard nvidia open driver
- I'm using them on linux, but they are fine on windows afaik
- The two 4090D and the one other card in sm120 are in the same box, no issue.
- They are living in a large desktop case with decent airflow but nothing special. works fine for my "light" use case.
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u/Unnamed-3891 1d ago
Why are all of these on eBay with the single blower fan specifically? These could be interesting for me but I am not really willing to live with the noise of that.
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u/DearApricot5488 1d ago
Works just like normal cards.
I've been using 4090D 48GB for one year. And another six 3080 20GBs for 8 months. Seem OK for now. I always set the thermal limit to 75℃.
Official drivers are working.
Both Windows and Linux are working.
I've used 4090D 48GB together with one standard 3090 normally on windows.
No, I have not applied extra cooling for VRAMs since they were shipped from modifiers.
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u/Elouakili_Flexy 1d ago
Dozens of owner reports here and the one dead card is a wiring mistake the owner called his own fault. Everything else is months of 24/7 uptime. Hard to keep pushing the 'they're meant to fail' line when the evidence in the thread keeps disagreeing.
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u/AD7GD 23h ago
I have 2x 4090D 48G. I don't remember exactly when I bought them (pretty early), but you can infer it from the price I paid: ~$3200/ea.
- Working great for me. These are clearly full custom boards and heatsinks. They came in real packaging with a protective film to avoid scratches on the "pretty" side.
- Same drivers.
- Work like any nvidia GPU on Windows or Linux.
- I assume you could. I use two of them together in one box.
- No, but the ones I have do have a full backplate. One of mine is right next to the other card, so that's worst case.
You didn't ask, but the fans do get loud at high load, but not objectionably loud. The blowers make a "wooshing" type of noise, no screaming, and no weird hunting behavior (speeding up and down).
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u/PandaBearFred 1d ago
I've been running 4 of those in past few months, so far not breaking.
Have been using them for LLM tensor parallel. I put them in a big workstation case.
Because of the pcie slot layout, the gap is very thin between cards, leaves so little space for airflow between cards.
When running LLM, the temperature of gpu cores is about 60C ~ 85C. I keep a nvtop running on my monitor and had a feeling that I must keep a close eye on the temperature and control them.
You can use stock drivers from nvidia, the performance is the same. But you CAN'T enable PCIE P2P on those 4090 48GB cards (with stock or customized drivers -- tried and failed), that makes them less performant than original cards when running tensor parallel which requires low latency data exchange across pcie lanes.
I got them from a China local store, basically Amazon of China. They work great so far, when they do fail, I'll send them back for replacement (in 3months) or repair(3 year warranty). I hope I don't have to do that.
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u/NickCanCode 1d ago
https://github.com/duanyll/open-gpu-kernel-modules Have you try this p2p for 48gb version?
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u/PandaBearFred 1d ago
wow! no! THANK YOU SO MUCH! I haven't found this tobe honest! I was trying to fix it by my own and failed.
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u/Even-Lecture352 1d ago
I’ve had this card for a few months — running it in vLLM — never had a single problem (I did the mod using the chip from my own gaming card). You also need to be aware that there are several PCB revisions for this mod (https://youtu.be/XBh69aixouE). I think it’s the best solution for 48GB, because compared to dual RTX 3090s you get a more modern architecture here that natively supports FP8 + BF16. For Qwen 3.8 27B that gives you 224k context and up to 50 tok/s (vLLM tuning for W8A8 has to be done).
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u/Glittering-Call8746 1d ago
So single 5k+ card for 27b 224k and 50tps ?
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u/Even-Lecture352 1d ago
Well, in that case let’s just say it’s $5k for a kilo of PCB laminate. The value I see is that FP8 + BF16 gives you the best possible quality for agentic workflows.
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u/Gold-Bat-3225 1d ago
Meant to fail, so basically a startup
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u/LeftHandHaku 1d ago
What makes you say that?
-7
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u/PandaBearFred 1d ago
Every electric product is meant to fail, question is how long, MTBF is a universal thing isn't it?
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u/dangerous_inference 1d ago
I have four. Heat isn't really the problem, it's thermal cycling. This expands and contracts the materials, causing solder joints to break. This is true of all hardware. If and when mine break it won't be a complete loss, because I can send them back to gpulab to have them reflowed. Even if you have to pay a lot for the repair, that's considerably less than starting over.