GPU confusion. Which one for a budget miner?

[Galane]

Or higher numbers on the product name don't always equal higher performance.

https://en.wikipedia.org/wiki/List_of_AMD_graphics_processing_units

I have $100-ish to spend on a GPU for mining scrypt coins, and also plan to do SHA256 along with a couple of block erupter sapphires (I got them really cheap) and will likely buy an Antminer U2 or two since they're faster and cheaper than the U1.

But right now I need a GPU that's not stupid expensive and won't be a gigantic waste of money due to it having a model name that makes it seem like it should be fast when it's likely one from the previous generation that was higher up the performance ladder will outperform it.

My electricity cost is 6 cents a kilowatt hour.

I bought a Sapphire Radeon HD 6870 with 1GB DDR5 in an auction lot, supposedly new but it damaged two motherboards. One was my olde Socket 939 board, the other was a $40 OEM Asrock 770 Extreme3. I figured that perhaps it killed the PCIe bus on the 939 from pulling too much power for a 1.0 spot, even though I had both 6 pin plugs connected to the board. I first tested the Asrock with an 8800GT, booted fine. Then I plugged in the 6870 and @#%@#%#%^%@#@%@!!!!!! Deader than the 939 board, which stops POST at 6b (if I had an old PCI video card it might still work). The Asrock just goes straight to FF. (I'm getting a replacement board, same model.)

If the card could be repaired cheaply... but Sapphire won't touch it, not even for $. If your Sapphire dies out of warranty, you're screwed.

The best GPU I have now is a nVidia 9800 GT 1GB. It averages 20-ish Khash on scrypt and can peak at several Mhash (I forget just how high, IIRC I saw around 100 with the latest BFGminer) on SHA256 but it won't maintain that top speed for some reason, varies up and down a lot.

I've been working with computers for over 30 years and have always been a bit of a cheapskate when it comes to buying hardware. I wait for prices to drop to what I consider non-insane instead of being an early adopter throwing money at the latest shiny object. I remember when hard drives first dropped to $1 a megabyte. 500 megs for $500! Then I was able to buy somewhat smaller drives for peanuts, and laugh at those who bought the 500's when the 750~800's came out for less than $1/meg.

[repairguy]

For that kind of money I would buy a used 6970/50.  You can find them around 100 bucks and get 470khs out of them pretty easy.

If warranty is what you are worried about XFX is lifetime, but they are known for using cheaper components(not necessarily that they fail easily but they don't overclock as well)

Also, takes me back.  Ever played duck tales?  I remember our second computer was so fast (cyrix 100mhz cpu) that you couldn't see the hook spinning on the rope.

[NuSalvo]

If your using a 9800 GT, I would look into cudaminer.  https://bitcointalk.org/index.php?topic=167229.0  You'll get much better kh/s with this program and can do scrypt, scrypt-jane, vert, and keccak.  The dev seems to be adamant about keeping one mining program to handle all the algos.

I understand wanting to save some money and get hardware that is a little older, but the new GTX 750 Ti seems to be a great kh/$/w card now that cudaminer has been heavily updated.  Look at this article  http://cryptomining-blog.com/tag/gtx-750-ti-cudaminer/  6 cards do 1625 kh/s at only 432 W... and $139 a card.    These are the R9 270's of NVidia.

[Galane]

I have been using Cudaminer. All the tweaking seems to be going into the newer nVidia GPUs.

I haven't done any mining since coinex went down. They're rapidly running out of "next week" to get things up and running and secure.

I'd love to know where to get a HD 6970 for $100. None on buy it now on ebay that low, but the lowest price there is less than any other place. The 6970 seems to be a hard card to find. Many sellers have the 6950 but no 6970.

[MinerP]

For that kind of money I would buy a used 6970/50.  You can find them around 100 bucks and get 470khs out of them pretty easy.

If warranty is what you are worried about XFX is lifetime, but they are known for using cheaper components(not necessarily that they fail easily but they don't overclock as well)

Also, takes me back.  Ever played duck tales?  I remember our second computer was so fast (cyrix 100mhz cpu) that you couldn't see the hook spinning on the rope.

you must have some 6970's sent from heaven to do 470khs

[dspair]

GPU mining is in a bad spot right now.

[baka]

For that kind of money I would buy a used 6970/50.  You can find them around 100 bucks and get 470khs out of them pretty easy.

If warranty is what you are worried about XFX is lifetime, but they are known for using cheaper components(not necessarily that they fail easily but they don't overclock as well)

Also, takes me back.  Ever played duck tales?  I remember our second computer was so fast (cyrix 100mhz cpu) that you couldn't see the hook spinning on the rope.

you must have some 6970's sent from heaven to do 470khs

They do 435 stock, 470 isn't really pushing it.

[jrrsparkles]

Based on some experiments I ran in late January, the R280x gave the best bang for the buck. I compared kw/h, hashrate and price at that stage.

Most of the other graphics cards were simply not cost-effective enough to be put into a mining rig.

[Reamer]

For that kind of money I would buy a used 6970/50.  You can find them around 100 bucks and get 470khs out of them pretty easy.

If warranty is what you are worried about XFX is lifetime, but they are known for using cheaper components(not necessarily that they fail easily but they don't overclock as well)

Also, takes me back.  Ever played duck tales?  I remember our second computer was so fast (cyrix 100mhz cpu) that you couldn't see the hook spinning on the rope.

you must have some 6970's sent from heaven to do 470khs

I'm able to get 450khs on an ASUS 6950 unlocked and oc'ed but never hit 470

[Galane]

Based on some experiments I ran in late January, the R280x gave the best bang for the buck. I compared kw/h, hashrate and price at that stage.

Most of the other graphics cards were simply not cost-effective enough to be put into a mining rig.

R280x = $399 != low budget.

[gsupp]

I understand wanting to save some money and get hardware that is a little older, but the new GTX 750 Ti seems to be a great kh/$/w card now that cudaminer has been heavily updated.  Look at this article  http://cryptomining-blog.com/tag/gtx-750-ti-cudaminer/  6 cards do 1625 kh/s at only 432 W... and $139 a card.    These are the R9 270's of NVidia.

I second this suggestion. If you can spend $160 instead of $100, you would do well to buy a 750 Ti card. The power to Kh/s ratio is very good for a GPU. If I could do it all over again, I would choose these cards.

[kalus]

R280x = $399 != low budget.

buy a used one.  they're going for cheap right now.  it's amazing what a cash offer does for an overcapitalized miner looking to pay rent in a few days. 

[elavenil]

simply use this calculation , GPU price/hash rate + power cost ,

[repairguy]

For that kind of money I would buy a used 6970/50.  You can find them around 100 bucks and get 470khs out of them pretty easy.

If warranty is what you are worried about XFX is lifetime, but they are known for using cheaper components(not necessarily that they fail easily but they don't overclock as well)

Also, takes me back.  Ever played duck tales?  I remember our second computer was so fast (cyrix 100mhz cpu) that you couldn't see the hook spinning on the rope.

you must have some 6970's sent from heaven to do 470khs

I'm able to get 450khs on an ASUS 6950 unlocked and oc'ed but never hit 470

I use all different brands and achieve the same result.
6950 shader unlocked or 6970 =470khs
6950 standard 430khs

I even get these rates on the extra cheap visiontek 1gb $169 refurbs (they have been running solid for a year now and I got over half of them to unlock)

and yes they came from heaven(newegg)