If you wait until next year then a GTX 960 might provide 80% of the performance of a GTX 970 for just 75% of the cost.

But if you want something now then the GTX 970 might be a good idea. We know that it costs 2.2 times as much as a GTX 750 Ti and uses 2.4 times the power, but it also provides 2.6 times the theoretical performance output so you might be able to get away with fewer cards.

What's a 'Serious Number Cruncher' ?
I'm running 2x GTX650 Ti at 1095MHz. Each card runs 4 concurrent seti MB tasks, each task taking about 1 Hour 45 minutes to run. That's about 110 tasks per day. Compared to CPU that seems pretty serious number crunching to me. My next rig is using 2x GTX750 Ti so interested in hearing how others have found these perform - when MB tasks are available in copious quantities.

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What's a 'Serious Number Cruncher' ?
I'm running 2x GTX650 Ti at 1095MHz. Each card runs 4 concurrent seti MB tasks, each task taking about 1 Hour 45 minutes to run. That's about 110 tasks per day. Compared to CPU that seems pretty serious number crunching to me. My next rig is using 2x GTX750 Ti so interested in hearing how others have found these perform - when MB tasks are available in copious quantities.

You're not doing yourself any favours trying to run 4 concurrent tasks on each of those cards. :-O

Running 2 tasks at a time on those cards should take around 25-30mins each task and will get you around 190-200 tasks per day completed.

Just because you can do that many doesn't mean that you'll do them in a productive or timely fashion. ;-)

Cheers.

Sorry for the typo should have 0.75 hours or 45 minutes. I was thinking of something else at the time. I've tried numerous numbers and the 4 gives better throughput per day. Uses 940MB of the 1GB memory on each card. When I've tried fewer concurrent tasks the points per day decreases, I guess there is idle time that isn't being used.

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What's a 'Serious Number Cruncher' ?
I'm running 2x GTX650 Ti at 1095MHz. Each card runs 4 concurrent seti MB tasks, each task taking about 1 Hour 45 minutes to run. That's about 110 tasks per day. Compared to CPU that seems pretty serious number crunching to me. My next rig is using 2x GTX750 Ti so interested in hearing how others have found these perform - when MB tasks are available in copious quantities.

That's about the same number of MB tasks one of my i5-4670K's @ 3.4GHz can do in a day for far less power.

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SETI@home classic workunits: 93,865 CPU time: 863,447 hours
Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[

Sounds like I need to review a few settings.

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I think the question is what does Herb consider serous crunching...

That term varies from person to person. With a single 750Ti I was averaging 17 Thousand. With 2 of them I was around 25 thousand. With the 4 GTX 750TI I think I was averaging 35 thousand.

Now, that might not sound like a lot but when you were only crunching a few hundred to maybe 1-2 thousand that's almost a 20 fold increase.

So for Herb, I would ask, what type of numbers are you looking for?

I for one think the configuration that you mention is fine with the exception of power, I would go a little higher maybe 750, 800, 850. But that can be updated later as you add more GPUs. For 2 it is fine, maybe even 3 but i think that would be pushing it.

My old machine that I spoke of still exist minus 1 GTX 750ti. It's over on Einstein currently but if you look at my computers here, you will still see it . It hasn't been on Seti in over 2 months. Once everything is back, it will migrate back here as well.

Good luck and if you have questions just ask.

Zalster

I think your choices are good.

The CPU is the Black edition so you can overclock if you want to.

The motherboard has enough slots.

That CPU cooler is popular.

All the 750 Ti I see at the moment will use up two slots, so a true single slot model will be needed for the fourth card unless you want to use a PCI-E riser.

There appears to be a single slot Galaxy 750Ti available direct order from them. Out of stock currently. They have single slot GTX 750 plain blower available though for around $100.

Keith

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Herb, unless it is an emergency I would not do anything for a couple of months. There should be a GTX 960 in the works.

You need cards that look like this:

http://www.evga.com/Products/Product.aspx?pn=04G-P4-1972-KR

The blower-type fan will exhaust the hot air out of the back of your case and that's going to be important for three or four cards on a board.

The 750Tis are nice and they are pretty good little crunchers,and they are cheap, but you said

"I would like to put my back up on a machine that can do some serious number crunching when it is just sitting there waiting."

I own almost all AMD CPUs.

The AMD CPUs are LOUSY crunchers. If you are going to run CPU tasks, you really need to re-think that choice. If you aren't going to run CPU tasks, then yeah, the AMD boards are cheaper as are the CPUs themselves, but they do burn a lot more power.

C'mon ..... AMD FX's aren't THAT bad at CPU crunching. ;o} That link is the very same cards I just put into my crunchers. Very happy with their output. Their double-precision FLOPS rating is double my old 670's over at MilkyWay and have seen a dramatic rise in RAC now that the cards are doing MW and Einstein in the current Seti drought. And agree completely that blower or reference design coolers are the way to go with a cruncher build. Best to exhaust all the hot air outside the case and not circulate it around the case for the CPU air cooler to inhale.

Cheers, Keith

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Sorry for the typo should have 0.75 hours or 45 minutes. I was thinking of something else at the time. I've tried numerous numbers and the 4 gives better throughput per day. Uses 940MB of the 1GB memory on each card. When I've tried fewer concurrent tasks the points per day decreases, I guess there is idle time that isn't being used.

First thing I did once the new 970's went in was to run SetiPerfomance and see where the sweet spot for concurrent tasks was. I figured with 4 GB of RAM aboard each card they could easily run 4 concurrent tasks per card. I never ran more than 2 concurrent tasks per card on the 670's with their 2 GB. Guess what ..... even with 4 GB of RAM on the 970's, the sweet spot for the cards is 3 concurrent tasks.

Cheers, Keith

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

I think it depends on which AMD FX chip you are talking about.

For a PURE GPU cruncher then the FX 8350 is fine. But I would recommend not crunching on that chip at the same time as you are supporting the GPUs.

I made the mistake of trying to crunch on both the chip and the GPUs and it would either lock up or restart on it's own. (I learned it common occurrence so don't do it)

I finally learned that is was better to just increase the amount of work units on each GPU (2 per 750) rather than have the Chip try to crunch.

I upgrade to a FX-9370 later and haven't had any problems but that was for a different machine with different GPUs. For the 750 I think the 8350 is fine.


Zalster

I think your choices are good.

The CPU is the Black edition so you can overclock if you want to.

The motherboard has enough slots.

That CPU cooler is popular.

All the 750 Ti I see at the moment will use up two slots, so a true single slot model will be needed for the fourth card unless you want to use a PCI-E riser.

There appears to be a single slot Galaxy 750Ti available direct order from them. Out of stock currently. They have single slot GTX 750 plain blower available though for around $100.

Keith

The Galaxy 750Ti that I saw had a single slot bracket but a double slot heat sink so it won't really fit in one slot. A GTX 750 isn't exactly the same thing.

C'mon ..... AMD FX's aren't THAT bad at CPU crunching. ;o}

<he says with a grin> They do out-run my old single a dual core Droid phones... that's true.

Of course, everything is relative. Relative to an i5, they are slow, and burn electricity like it's going out of style per WU they complete.

Using them for nothing more than GPU-support seems to be fine and they are inexpensive to buy. That's why I have them --> cheapness of the part plus a board.

CPU-crunching is a losing proposition anyway unless it's all you can do or the project you want to crunch only offers CPU work units.

I've got some awfully slow CPUs crunching but only because I really wanted to crunch some of the project they crunch and that project only offers CPU work. I would prefer to use the GPU, but that machine doesn't have a usable GPU.

I have found that if I don't care about my power bill I *can* crunch eight GPU work units and one CPU work unit on the 8350 simultaneously. Two is iffy and "depends" and three slows everything down no matter what.

At Newegg found MSI N750ti 2GD5TLP GeForce GTX 750ti that says it is a single slot. The picture that come with it shows it be single slot. The fans on it may hang over the adjunct slots. I will start with two and then evaluate for next steps.

Thanks

Herb

You can use three of those cards without a problem. A fourth card would have to go in the black slot where the fan would hit the card in the next slot.

I think the question is what does Herb consider serous crunching...

That term varies from person to person. With a single 750Ti I was averaging 17 Thousand. With 2 of them I was around 25 thousand. With the 4 GTX 750TI I think I was averaging 35 thousand.

Now, that might not sound like a lot but when you were only crunching a few hundred to maybe 1-2 thousand that's almost a 20 fold increase.

So for Herb, I would ask, what type of numbers are you looking for?

I currently have 4 machines running for my own tasks. But being lazy and not liking to wait for them to boot I have always left them running 24x7. So why not let them do something useful when I am not at the keyboard. Currently generate about 5800-6100 credits a day. The machine I am upgrading generates about 1700. Looking for a sweet spot between $$$ and credits. So a machine that gets 30,000 would be big step up.

I noticed in your example a pretty good decline in output for each additional each card. What is the reason for this? What if anything can be done about it? Mixed GPU types, a different mix of Seti and non Seti tasks? If I am going to burn the electricity might as well get as much as possible from it.

Herb

All the cards are the same type.

I can't give you a good reason why there is a decline only to say that I too expected a 2x increase after the second and was surprised as well and watched to see what happen after the 3 and 4th.

All work was same type and from same project. I don't like to mix project work units since they impact on each other.

But overall the productivity did go up. Any answer I give would be a guess.

So I just state what I've seen without know why. I'm sure someone where can explain why.

Hmmm.... actually haven't any issues crunching SETI MB and AP CPU tasks at the same time as crunching on the dual GPU's. I do set aside 2 cores just to feed the GPUs and only process 6 CPU tasks concurrently with the GPU work. Might have to reduce the number of CPU cores processing further once we get SETI work again as I am now crunching 3 tasks per GPU now and I have noticed the CPU utilization is much higher for these 970's as compared to the old 670's. The CPU utilization pretty much stayed around 90% when crunching on 6 cores with the 670's. I did have settings to knock out 1 CPU task whenever 2 AP tasks hit the same card at the same time though. Its nice to have SIV system monitor and ProcessLasso running all the time to tell me what the utilization of system resources are at every moment.

Keith

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

I think your choices are good.

The CPU is the Black edition so you can overclock if you want to.

The motherboard has enough slots.

That CPU cooler is popular.

All the 750 Ti I see at the moment will use up two slots, so a true single slot model will be needed for the fourth card unless you want to use a PCI-E riser.

There appears to be a single slot Galaxy 750Ti available direct order from them. Out of stock currently. They have single slot GTX 750 plain blower available though for around $100.

Keith

The Galaxy 750Ti that I saw had a single slot bracket but a double slot heat sink so it won't really fit in one slot. A GTX 750 isn't exactly the same thing.

Actually, I did see a picture of the 750Ti card online when I researched and it was a true single slot width at only .83 inches wide. The picture was definitely a single slot width. When I looked at their website, the product doesn't match the initial product announcement. This is what I am typing about:

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http%3A%2F%2Fwww.techpowerup.com%2F206212%2Fgalaxy-intros-single-slot-geforce-gtx-750-ti-razor-graphics-card.html&ei=LYF_VJWgJImZNpKbgYAO&bvm=bv.80642063,d.eXY&psig=AFQjCNF5Cg7h-ooC6VeVzv2B0r53EK2tgg&ust=1417728692577542

The 750Tis on the Galaxy site have a single slot backplate but look to have a 2 cards wide heat sink. Won't work in Herb's desired configuration. Might be smartest to just settle for two, medium priced 2 slot cards and use them in the two X16 slots on the motherboard. Also the system would stay a lot cooler.

Keith

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

I suppose there's something available for non-US markets, I myself try to avoid buying from overseas merchants.