RTX 3080 on a PCIE 2.0 board? Good or bad idea?

[toTOW]

I'll be having the same issue ... my systems are old and from the first i7 generation, limited to PCIe 2.0 ... I hope they'll still be able to run the new GPUs fine, I don't plan to replace them until they die ...

[MeeLee]

As far as a 2080Ti becoming $250, probably not within this decade.
Look at the 1080 Ti,
That old tech is still sold for $750 cheapest on second hand sites.

1080ti now on ebay for around £300 - $360
2080ti for £500 - $600

prices are falling in expectation of the $499 RTX3070. If stock is as low as some predict, 2nd hand prices will rise again.

I guess you're right!
I guess they're falling a lot faster than when the 2000 series GPUs came out.
I'm thinking it's probably because the 2000 series wasn't enough to have many people switch over, and many still are running GTX GPUs.
Now, the 3000 series have become affordable enough, with a big enough performance gain, that it gets both GTX 1000 series, and RTX 2000 series users on board!

[istvan700]

So did anyone manage to handle an rtx card with a PCIE 2.0 mbo?

[bruce]

The performance will be degraded somewhat, depending on the size of the project being assigned but it'll still run.

[psaam0001]

I have my "Dream Lists" of new folding hardware set up on NewEgg's website.

Whether I build my "Kick COVID-19's rear end" system, or not will be based on what I can afford. And right now, adding a GT 1030 to my 16-core system's 2nd PCIe x16 (electrically x4) slot is the best I can do at the moment. As I want to save up for another 3950X CPU to upgrade the computer my dad uses in the near future (I'll be putting that 3200G in a non-folding system).

There will be no resurrecting that Socket 775 system--I'm donating the Q8300 for use in another system that I am not the owner of. Should someone need a 2-core Core 2 CPU, PM me for info--it's free.

Paul

[elblat]

So did anyone manage to handle an rtx card with a PCIE 2.0 mbo?

Well, An RTX 2060. It seems to run about 20% slower than in an x570/Zen3, but I'm thinking it may be a limitation of the old CPU I've got on that board. Doing the overhead tasks (start/finish/checkpointing) take a rather significant amount of time compared to when the card is serviced by the more modern processor. The 2.0 bus apparently never maxes out (reporting ~60% max utilization). In addition, that old board has a GTX 1650 in another slot, but I see no evidence in the numbers that that causes any slowing. All of these observations are taken under linux.

[bruce]

(start/finish/checkpointing) does take CPU resources. Some of that can overlap with the other activities that CPU has to do ... including moving data across the pcie bus. While it's doing a checkpoint the GPU is usually idle and unless they've improved the software so there's a bit of time spent reloading the data to start the next time-step, and while that may brief, it matters when the bus is busy doing something else. 60% utilization is higher than I like it to be but at least it's being driven by Linux.

Is RAM constrained, too?

[elblat]

Your assumption appears to be correct, the GPU reports idle during that time. There is plenty of RAM but it is DDR3 1333 so, as you suggest, there my be additional delay there too.

I feel that it is worth running these GPUs in this system because they pull very little power in the idle state, and the CPU/mobo dissipate ~70W, so the points/joule is likely not much worse than a modern setup.

[bruce]

I feel that it is worth running these GPUs in this system because ...

We do get frequent questions about why others report higher PPDs that I'm getting ... and they're valid questions, but if I'm getting more in my present configuration than I might be with minor tweaks to the configuration, all is good!

[antropodos]

HI.
I bought an RTX 3060 TI and it does not give video signal (no signal) already with the drivers installed, I have an i7 2600k and a GA-Z68XP-UD3 motherboard with PCIE 2.0.

Can it be solved with a BIOS update?

[MeeLee]

PCIE 2.0 x16 bandwidth is like 3.0 x8 and 4.0 x4 speeds.
It's sufficient for even an RTX3090.
However, the underlying hardware may indeed be too slow.
For a 3080 you'll need at least a 4Ghz CPU core, which are harder to find.
I'm not sure how Hyperthreading/SMT affects this (eg: if a ~3,6Ghz with HT will be able to keep up with such a card).
Memory speed also adds another latency factor, though it shouldn't be by much, as most of the data going to the GPU is buffered in the CPU's L-Cache anyway.

HI.
I bought an RTX 3060 TI and it does not give video signal (no signal) already with the drivers installed, I have an i7 2600k and a GA-Z68XP-UD3 motherboard with PCIE 2.0.

Can it be solved with a BIOS update?

Depends on the motherboard. Most likely not.
If however, you can boot the PC, it might.
If the PC doesn't do post bios, it may be incompatible, and your motherboard may be limited to GTX GPUs.