The price on 280x has gone up to around $400 USD (700kHash), would it be smarter to buying two 270x for $400 ($200x2)? They should provide 450-500kHash each.
IMHO no. Im very new to this, but I think you are well better off opting for the 280x.
Im not sure where you buy your cards from, but I can get 280x's well below $400
What are your plans for the future? Getting 2xgpu now might limit your expandability later on, or it might be good - you could sell one of the 270s once it's paid itself off and replace with a 290.
the thing to look at here is how many watts 2 r9 270s use vs a single r9 280x.my 280s draw somewhere between 200 and 250 watts each. I think the 270s draw 180-200 each (going from what I saw on the hw comparison).so yes, you'll be hashing more with the 270s (will the 270s really do 500? I thought the hw comparo list was in the mid 400s, but either way...) but you'll also be using almost twice as much watts to accomplish the same task.if you have free energy, by all means get whatever you can get your hands on. otherwise, factor in the electricity costs into your determination if it is worth it or not
anyone can help me to configure my cgminner on Gigabyte r9 270x im newbi.. pls!
I need some help too...
Hi guys, welcome to mining, please see the "Miner Configs" section of the forum, or on your dashboard click on Support > FAQ for assistance.
I'm averaging exactly 477 at the moment using R9 270x gigabyte card. I would like to add cards as more funds become available. dfalcon I look forward to hear how you make out with a multi card set up.
mekks I would use what you have available, if it is profitable as far as cost of electricity
To close the loop a bit, I ended up picking up a few ASUS TOP OC'd edition 270x's on sale (the one's that come already at 1120 Core/1400 Mem). As great as they are I'm running into the 450k/h barrier. Can those who are getting 470+ elaborate any?
Im getting 479 steady on Gigabyte card. I picked up a Diamond r9270x and could not run the same parameters as the Gigabyte card without crashing cgminer. The Diamond is running at around 424, however very stable though. They are the same chipset yet not the same hash rate which you would think they would be at least close. I haven't done much tweaking yet with the Diamond but don't expect much more.
One issue I am having with the above set up is keeping cgminer stable for over 12 hours. It randomly stops responding (3-12 hours in) and I'm forced to restart cgminer. The error that appears in cgminer is something along the lines of a thread already existing, the GPU doesn't respond for over 30 seconds, and it declares it SICK. Then the cgminer application stops responding in Windows. I click the "Close" button, restart the miner, and all is well for another ~3-12 hours. I turned verbose on, didn't tell me anything new.
Turn your memory clock down from 1500. Are you running windows?
Yessir, Windows 7 x64 on both machines.
dfalcon that is odd. Have you tried any settings from the hardware comparison chart? When setting are incorrect for me, I get a windows error about driver stopping and then cgminer stops. Are you getting the window error? I;m running 2 x 270x on a 850w I don't think you should have issue with PSU. I would try getting the single card going then add multiples. I usually let it run for 1 or 2 days with out a crash before determining no issues.
I'm having issues with stability anytime I try to tweak my setup. I am using ASUS R9 270x on Xubuntu.
SGF-I would turn down memclock and engine till stable. I played with that and have stabilized the diamond card at 460khs. I had to turn down 1050/1400.
Dfalcon413 - you should be able to run at I19 all the time.
user1888- I'm not getting anywhere near 460 numbers with the memclock and engine at those levels. I do agree that the higher numbers there are causing my instability. Are you using -g? If so 1 or 2? what is your Intensity set too, and are you using -w 256, and what is your thread concurrency?
Im using Intensity of 19. I'm not in front of my pc but I believe gap is 1. I am using 256 on diamond card. thread is 14000 range.