Sapphire 7870 - 159.99$ AR on Amazon

[CrimsonGT]

Hey Guys,

I have not seen any good deals since I picked up my R9 280X for 299.99$ earlier this month. However, my roommate just stumbled across this on Amazon when building his new computer. I just grabbed 2 of them and it looks like there are still 10 left in stock.

http://www.amazon.com/gp/product/B00A2J4ROE

From reading other threads, it sounds like these net around 415kh/s. Not bad for about 830kh/s at 320$.

[RB25]

Mine are running stock and averaging 320kH/s on I12. I have two and they are really solid.

[CrimsonGT]

Glad to hear that. It looks like with some different tweaks they range anywhere from 350 - 415kh/s. I am curious what the Watt usage on these cards is as I am going to need another PSU for them

[RB25]

Glad to hear that. It looks like with some different tweaks they range anywhere from 350 - 415kh/s. I am curious what the Watt usage on these cards is as I am going to need another PSU for them

I think I was reading 175W at full load for each card. It stock settings, I should be well under that. I have 2 running on a 700W PSU and have had no issues. I would push them harder, but the PC is my main work/play desktop so I can't risk frying it.

ETA: According to Sapphire's info, the 7870 Ghz Edition runs at a max of 175W.

[zneww]

i bought mine off newegg and it was the same deal. ive got it at 380kh/s steady. could get higher but it crashes after long times and thats not cool lol, i love it tho

[Victoo]

Good to see this at that price. Will try to find more deals like this on Amazon.

[kcobra]

Last week I ordered 5 of these from Newegg. Just got them in today and got 3 running using BAMT 1.1.1. No long term numbers, as I just got them running, but here's my stats from cgminer:



My cgminer config:

Code:

"intensity" : "20",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"thread-concurrency" : "15508",
"shaders" : "0",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"gpu-engine" : "950",
"gpu-memclock" : "1365",
"gpu-powertune" : "0",
"auto-fan" : true,
"gpu-fan" : "50-90",
"temp-target" : "78",
"temp-overheat" : "85",
"temp-cutoff" : "90",
"temp-hysteresis" : "3",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "60",
"scrypt" : true,
"shares" : "0",
"kernel-path" : "/usr/local/bin"

Kill-a-watt meter shows right at 600 watts from the wall. Using one XFX 650 watt PSU. Sempron processor, 2 rams sticks, usb thumb drive boot, no hard drive, no cdrom drive, etc.

[RB25]

Kill-a-watt meter shows right at 600 watts from the wall. Using one XFX 650 watt PSU. Sempron processor, 2 rams sticks, usb thumb drive boot, no hard drive, no cdrom drive, etc.

I'd be leery about running the power that close to the max. If I got a 3rd card, I would probably get a 800 or 900W PSU for a little comfort zone. Just my opinion.

[kcobra]

Kill-a-watt meter shows right at 600 watts from the wall. Using one XFX 650 watt PSU. Sempron processor, 2 rams sticks, usb thumb drive boot, no hard drive, no cdrom drive, etc.

I'd be leery about running the power that close to the max. If I got a 3rd card, I would probably get a 800 or 900W PSU for a little comfort zone. Just my opinion.

Always good advice to have some headroom with the PSU. The XFX 650w one should be ok though. It's pulling ~600w from the wall so it's only putting out ~500w on the computer side. Also, it's a rebadged Seasonic so it's a quality PSU.

With all that said, I woke up this morning with the whole system dead. Cards were still spinning but no video. Quick debugging before work pointed to the motherboard flaking out. Perhaps running three 7870 cards through un-powered PCI-E extenders put to much strain on the motherboard or maybe it was just it's time to go. Will have to start replacing components tonight to figure out the problem.

[RB25]

Kill-a-watt meter shows right at 600 watts from the wall. Using one XFX 650 watt PSU. Sempron processor, 2 rams sticks, usb thumb drive boot, no hard drive, no cdrom drive, etc.

I'd be leery about running the power that close to the max. If I got a 3rd card, I would probably get a 800 or 900W PSU for a little comfort zone. Just my opinion.

Always good advice to have some headroom with the PSU. The XFX 650w one should be ok though. It's pulling ~600w from the wall so it's only putting out ~500w on the computer side. Also, it's a rebadged Seasonic so it's a quality PSU.

With all that said, I woke up this morning with the whole system dead. Cards were still spinning but no video. Quick debugging before work pointed to the motherboard flaking out. Perhaps running three 7870 cards through un-powered PCI-E extenders put to much strain on the motherboard or maybe it was just it's time to go. Will have to start replacing components tonight to figure out the problem.

You sound a bit more experienced, but I want to make sure that new people realize that just because a PSU says 600W and your 3 cards say 150W max, there are other components and circumstances where damage can occur so its best to leave yourself a buffer for power usage.

[kcobra]

Yep, definitely agree. Also, way to many crap PSU's out there that people try to use. Best investment a miner can make is a Kill-A-Watt meter.

Side note: Anyone recommend a place to buy powered PCI-E extenders that are known to be good quality?

[zneww]

Yep, definitely agree. Also, way to many crap PSU's out there that people try to use. Best investment a miner can make is a Kill-A-Watt meter.

Side note: Anyone recommend a place to buy powered PCI-E extenders that are known to be good quality?

There are a bunch in the Goods > Computer Hardware section of BitcoinTalk. Bunch of reputable guys