Q about k/h hash rate on higher end cards..
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Hi pyxis. Well, I have 16g myself. It was more of my friend speculating about the processor. Just out of curiosity, I’ve always thought overclocking takes away from the longevity of the cards, am I mistaken?
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[quote name=“J4c0b5L4tt3r” post=“4623” timestamp=“1369089761”]
Hi pyxis. Well, I have 16g myself. It was more of my friend speculating about the processor. Just out of curiosity, I’ve always thought overclocking takes away from the longevity of the cards, am I mistaken?
[/quote]No your not, it does cut down the life, but the way I see it, you make more now rather than later with coins. My main worry now is summer, if its gets too hot i will have to reset the cards back to 615Khash at normal settings.
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As you have discovered, the CPU does nothing to aid in the the performance of GPU miners.
Also, the amount of RAM makes no difference to the latest versions of CGMiner either. I have 4x 7970’s hashing at ~755KHs each on rigs with 4Gb RAM but CGMiner only uses ~150MB. I still have 2.6GB Available (1.2GB free).
Overclocking the cards doesn’t noticably affect the longevity of cards - Over volting and/or heat does. Keep 'em cool at stock voltages and you’ll be fine.
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@pyxis Yeah, I’ve already had a casualty from the heat. I’m glad it’s still under warranty… Although, it may be a few days before I’m full steam again… I just shoot for the highest hash rate with zero h/w errors… I’ve been pretty lucky so far… Well I hope it stays cool for you:)
@Nutnut I’ve kept all mine stock, but I have been having issues with the heat, which I’ve been trying to remedy… So far I think I may have it worked out, but only time will tell…
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Let’s be clear about this: The amount of ram required is trivial. More ram won’t help. The amount of hashing a CPU can do is minuscule compared to a GPU. A i7 quad xeon should get about 24 Mh/s, a 5770 running on an i3 will get 250 Mh/s when tuned correctly. The bang for your buck is easily in favor of GPUs.
Number one factor is CPU/GPU speed. That’s basically ALL that matters. When running scrypt, you MAY get a few extra Kh/s by overclocking your GPU ram if your running more than 600 Kh/s, but even then the limiting factor is going to be your GPU clock speed by far and away. When doing it on your CPU, you’re never going to max our your ram, nor your bus. Ever. The CPU will be pegged, and your DMA controller will be practically idle.
You see those little USB BlockEruptors? I bet then don’t have more than a few megabytes of ram on them. Notice I said megabytes, not gigabytes. Yet they outperform a 5770 with gigs of ram. It’s ALL in the Ops/second, not the storage size.
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When i first build a rig with 1x 5850 i got 512MB ram installed, which caused 80 HW errors, then someone mentioned at bitcointalk that i should add more RAM, so i got 2GB instead of 512MB and the HW errors are gone.
So at least it’s doing [i]something[/i] with ram… -
[quote name=“Kevlar” post=“5219” timestamp=“1369199124”]
Let’s be clear about this: The amount of ram required is trivial. More ram won’t help. The amount of hashing a CPU can do is minuscule compared to a GPU. A i7 quad xeon should get about 24 Mh/s, a 5770 running on an i3 will get 250 Mh/s when tuned correctly. The bang for your buck is easily in favor of GPUs.Number one factor is CPU/GPU speed. That’s basically ALL that matters. When running scrypt, you MAY get a few extra Kh/s by overclocking your GPU ram if your running more than 600 Kh/s, but even then the limiting factor is going to be your GPU clock speed by far and away. When doing it on your CPU, you’re never going to max our your ram, nor your bus. Ever. The CPU will be pegged, and your DMA controller will be practically idle.
You see those little USB BlockEruptors? I bet then don’t have more than a few megabytes of ram on them. Notice I said megabytes, not gigabytes. Yet they outperform a 5770 with gigs of ram. It’s ALL in the Ops/second, not the storage size.
[/quote]Not entirely accurate. :P
SHA-256 is GPU intensive and OC’ing the hell out of your GPU pays dividends. In fact, when i mined BTC i under-clocked my RAM to save power and lost nothing in hashrate. We agree there.
Scrypt on the other hand is very memory intensive though its your video ram that takes a hammering. The GPU certainly helps but just OC’ing as fast it can it will usually result in a drop in hashrate. Tuning the RAM speeds results in significant increase (around 150KHs on a 7970). Notice i said tuning not OC’ing as high as possible. The GPU on my cards is stable 1150 for btc. With scrypt however i run at 1080 and tweaking the RAM to 1500 (from 1375) makes my 7970 fly.
GPU speed is not all that matters.
All that said, the quantity of video RAM is not that important but the number of stream processors is and that’s why [s]ATI[/s] AMD excels over nVidia for mining. System RAM, as long as you have enough to boot the OS and bit extra you’re good to go. 2G is a safe bet.
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Have 7970 both on 16x and 1x slot on same system.
theres no difference in hashing power between them.
mining doesnt require much bandwidth speed. 1x is more then enough.
gaming on the other hand you should have 8x or higher for highend cards -
[quote name=“svennand” post=“6074” timestamp=“1369412351”]
Have 7970 both on 16x and 1x slot on same system.
theres no difference in hashing power between them.
mining doesnt require much bandwidth speed. 1x is more then enough.
gaming on the other hand you should have 8x or higher for highend cards
[/quote]That’s correct, because with gaming you’re moving a butt-ton of textures in and out of memory, and performing matrix transforms on the geometry at your frame rate. With mining, you’re uploading code once, occasionally changing a few parameters, and getting any results it produces, so memory bandwidth is minimal from your bus to your GPU.
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So what is the best bang for the buck card to get? Since my GPU just died…
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[quote name=“J4c0b5L4tt3r” post=“4238” timestamp=“1368824975”]
Thanks ChristianRiesen, I have a feeling you and ShadowEW are right. Although, my friend still wants to see what the i7 will do. I won’t complain though, because I’m getting an i7 out of it;)
[/quote]Haha hell no, tell him it’s making a big difference, so they don’t say “Ohh give it back then !!!” ;)
I knew people like that… lol
From what I’ve read, it’s not the speed of the bus that matters, as it’s not dealing with complex geometry that it has to spit out to the monitor at the same time dealing with CPU calculations to create a ‘world’ you run around and pew pew in.
It just gets sent a bunch of numbers, sits there contained in it’s little world and does it’s magic… and sends back the results.
But when it comes to things like numbers and maths I’m a blind man crawling around in a room full of 10 cent coins that feel like 1 dollar coins, and I don’t know if Im rich or not doing it right.
Oo
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Yeah, he took it back, but it wasn’t a big deal. Nothing improved… I like your analogy… Although, I’m not a big gamer…