2x XFX DD R9 280x, bad idea?

T

turboturd

n00b
Joined
Dec 30, 2013
Messages
4
I recently ordered a pair of XFX Double D 280x's planning to use them for LTC mining and gaming but I've just read terrible things about how hot the VRM gets due to lack of proper VRM cooling. The two PCIe x16 slots on my mobo (ASUS P8P67 B3) aren't spaced apart either, so this is especially worrying. Can anyone confirm my suspicions? I've purchased a 120mm Scythe Slipstream to use as a side intake, will that help? Should I just get rid of these and try to get a reference 290x? :confused::confused:
Thanks for any help
 
If you have no space apart you will get a total throttle-fest even at 100% fan speed each and dual high-flow side fans. I know from personal experience unfortunately (Corsair 300R case), with three high-powered fans on exhaust and sides; and two powerful intake fans too. And I *do* have a slot between the two cards... and they STILL throttle even with undervolts and underclocks. But if you are running just one alone it's fine, relatively quiet and decent-cooling.
 
For mining the two 280x's will do better. For gaming the 290x might be the more trouble free experience. Your P67 will have 1 extra slot in between the two cards (unless its the micro-atx board) but they will get hot, I can promise you that.
 
a single slot space is just not enough. In all of my rigs with just 1 space between GPU's they run WAAAAY too hot. No space is horrible. The design of the coolers are to pump the heat into the case. The only cards you can put close together are those blower wheel reference type coolers which are designed to pump the heat OUT of the case but are very noisy for things like mining. I love them though and WISH 280x's used them.

You'll have to go with hanging them. If you actually got a good deal on the cards though you've got a shot at getting your money back though as long as you don't register them
 
Good airflow is a must. Side intake fan absolutely necessary, and 1 or 2 front intakes important too.
 
blastingcap said:
total throttle-fest
Click to expand...

Is it the top card that's throttling or are they both? I'm trying to decide between keeping one in my system and getting a newegg refund on the other, or trying both and selling one used if the setup is shit. They should be arriving today or tomorrow.
 
turboturd said:
Is it the top card that's throttling or are they both? I'm trying to decide between keeping one in my system and getting a newegg refund on the other, or trying both and selling one used if the setup is shit. They should be arriving today or tomorrow.
Click to expand...

Top, but YMMV depending on your case and airflow and ambient temps of course
 
Cards have arrived. Installed the first one, greeted with these temps after half an hour of mining. Clearly my cooling setup and my tiny CM 430 Elite aren't quite ready to handle two of these.
At least I'm getting good hashrates right out of the box (650-720 KH/s)
abb.png
 
wow those vrm temps 0_0. I ordered 2 ASUS DC2T 280x's a few days ago, but they wont be here for another week or 2 probably.
 
Are DD's known for being adequate coolers?
I haven't seen anything good about XFX since they switched to AMD, aside from their warranty length (but nothing about their RMA service).

If you're planning on pushing a card like that, the first thing you need to do is check the cooler quality, any company that can skimp on vram/vrm cooling and get away with it is going to do so.

XFX's USA warranty used to support removing the cooler, you might be able to take it off and put some vrm heatsinks on there.
 
I'm not that into the mining scene so my information could be off.

However from what I had heard the XFX cards generally were not preferred for mining due to how they handled under the load. Incidentally you also noticed a greater availability (comparatively speaking) of the XFX cards after the mining demand hit.
 
If you are running them inside a case, you are gonna have a bad time. I have two running with 1 slot between and a box fan blowing on them in a room that is probably 74F and my VRMs are running at 80-90C. That undervolted to around 1140 (still tweaking), but are otherwise rock solid. Video cards run hot, hashing makes them run hotting. Not totally unexpected.
 
turboturd said:
Cards have arrived. Installed the first one, greeted with these temps after half an hour of mining. Clearly my cooling setup and my tiny CM 430 Elite aren't quite ready to handle two of these.
At least I'm getting good hashrates right out of the box (650-720 KH/s)
abb.png
Click to expand...

How much better does it get with fans at 100? Also maybe with side panel off? Just curious, if you have the time.
 
Terrible card for mining, I snagged one for $299 so I'll keep it, but all by itself (no case and an extra 140mm fan blowing on it) it overheats at stock clocks. And of course it's xfx, so no replacing the crap heatsink or even TIM without voiding the warranty, they have stickers on the screws.

FWIW I average 690khs with that one card, but I can't add another even two slots away without both overheating.
 
ITSTHINKING said:
How much better does it get with fans at 100? Also maybe with side panel off? Just curious, if you have the time.
Click to expand...
Not much better, at stock clocks. In fact VRM1 temp kept climbing until it peaked at 112 last night.

_r2h said:
If you are running them inside a case, you are gonna have a bad time. I have two running with 1 slot between and a box fan blowing on them in a room that is probably 74F and my VRMs are running at 80-90C. That undervolted to around 1140 (still tweaking), but are otherwise rock solid. Video cards run hot, hashing makes them run hotting. Not totally unexpected.
Click to expand...

I've lowered the voltage to 1050 and dropped the core clock to 950 MHz and I'm getting these temps so far:
k27.png

Very happy with this, seeing how cramped my case is. It might not be very stable though, I'll see. Hashes have dropped by around 100 KH/s however. More Scythe case fans are on their way.
 
Last edited:
how are you guys getting such high hashrates with these cards? i have an XFX r9 280x black and the max i've been able to get after weeks of tweaking is barely above 600khs. that's at 1140/1500!

cgminer.bat as follows: -d 0 -w 256 -v 1 -I 13 -g 1 -l 1 --thread-concurrency 8192

not only that but it regularly throttles and cuts back another 50-70khs
 
Great improvements man! Is that with 2 cards or just the one? If only you could replace the TIM, but the sticker prevents you :/
 
mmmsandwich said:
how are you guys getting such high hashrates with these cards? i have an XFX r9 280x black and the max i've been able to get after weeks of tweaking is barely above 600khs. that's at 1140/1500!

cgminer.bat as follows: -d 0 -w 256 -v 1 -I 13 -g 1 -l 1 --thread-concurrency 8192

not only that but it regularly throttles and cuts back another 50-70khs
Click to expand...

Your intensity and thread count are way too low!!!

This is what I use on my XFX 280x - 1050/1500, undervolted to 1075mV running 24/7 at 62~64 deg F on the GPU and 80~85 on VRM's. Fan set to auto. All through MSI Afterburner:

--gpu-platform 1 -d 0 -w 256 -v 1 -I 20 -g 1 -l 1 --thread-concurrency 20992

Get 690khs
 
I have 2 of the gigabytes and there's no way they could mine... They hit 92C with no problem mining in a closed case.

These custom cooled cards on Tahiti's are an issue in xfire. The way to make this work enough to not give you a heart attack, is a side fan... i would recommend going with the biggest one you can, use it for exhaust and upgrade your intakes. If you pound a lot of air into the case from the side, you better have some strong exhaust fans going.

Below script was knocking out 760/kh on my 280x's

Code: 
cgminer.exe --scrypt -o stratum+tcp://global.wemineltc.com:3334 -u .1 -p  --worksize 256 -g 2 -I 13 --lookup-gap 2 --gpu-engine 1100 --gpu-memclock 1500
 
Venomous said:
I have 2 of the gigabytes and there's no way they could mine... They hit 92C with no problem mining in a closed case.
Click to expand...

Is that 92C on the GPU or VRM's?
I usually start backing off when I see VRM's reaching 90C... :eek:
 
mzs_biteme said:
Is that 92C on the GPU or VRM's?
I usually start backing off when I see VRM's reaching 90C... :eek:
Click to expand...

Vrms and the core wasn't to far behind. This is where blower coolers or watercooling have the advantage. During gaming these cards never hit above 71c
 
You must log in or register to reply here.
Back
Top