Which specifications are important for a GPU to get a high Hashrate.
- GPU Clock Speed
- Graphics Ram Type
- Memory Bus Width
- Memory Speed?
or another important thing?
First I just want to verify with you, the 290X has 2816 stream processors and a 512 bit memory bus.
I'm quite new to this mining but found some information you may find quite useful. It's from another thread about GPU specs affecting mining performance: https://forum.ethereum.org/discussion/3924/gpu-key-specs-for-high-hasrate
It all seems to depend on which hashing algorithm we're talking about. I basically got that memory bandwidth has a huge affect on the hashrate of the GPU, and that in some cases you can even under-clock the core clock to achieve higher efficiency while mining. One guy in the thread made a spread sheet with some benchmarks he ran on several cards which claims that GCN 1.0 cards performed the best with modern cards falling short. So Radeon HD 78XX , HD 79XX, R9 2XX cards do quite well.
As for how the specs affect the hashrate? Really all I've found is higher memory bandwidth is key. Also, before you go buy like 4 Fury X's with HBM memory, keep in mind that memory is clocked much lower than GDDR5 memory, so the effective memory bandwidth is not as crazy high as one might hope for. I've got a MSI Lightning R9 290X and am considering getting into ether mining so I'm curious as to what others here have to say. Check out the link I pasted, as it's pretty much got this exact discussion going.
The number of processors on the board:
Example a AMD R9-290x has 8192 Stream Processors on the board.