Knights Landing reservations

[ewmayer]

Originally Posted by Prime95

Maybe get access to the Intel tools and use their emulation software for development until Purley comes along in 2017? Or we might only need the emulation software if gcc / HJWASM generates AVX-512 code.

As you know, the problem there is that emulation is fine as far as code correctness, but tells you nada about performance, nor about real-world-run stability, a nontrivial issue when it comes to complex, demanding multithreaded applications. (As your own code showed not too long ago with early-release Skylake systems.)

On the theme of possibly cutting the dev-system cost: Do we really need that big honking 96GB blob of DDR4 memory? I don't envision doing anything that would need more than 4-5 GB of RAM, which would fit easily in the 16 Gig of fast MCDRAM. What say my fellow would-be KL developers? I mean that DDR4 has gotta run at least $10 a gig, so running without it, or with some lesser 'system minimum' amount (if that is in fact required) could save a nice chunk of money. Similarly, perhaps look at an air-cooled system with just the SSD, i.e. sans the 4TB HD included in Colfax's standard offerings.

David, thanks for setting up the GFM page ... I feel we're pretty close, some combination of cost-cutting, 2-3 more interested-developers and a whiff of public charity via GFM should allow us to pull the trigger on this.

[airsquirrels]

Originally Posted by tServo

Have you considered the water cooled system?
...
I know this is early, but what would be the logistics for actually using this system wrt distributing the available time?... I think a dialog on this topic would be healthy.

I am most likely to purchase the water cooled version and make up the difference myself if needed. I run a lot of systems 24/7 and hands down have much better reliability and easier temperature management, even in cooled racks, using water cooling.

With regards to time sharing, I imagined we would have a thread here to informally track reservations. My only request would be that we setup so that when the system is not actively in use for development or test runs we run mprime or similar on it. This could even be automated to run anytime there were no active `screen` sessions or ttys.

Originally Posted by GP2

Since you've gone ahead with it, might as well make a sticky thread.

I'm not sure what needs done to accomplish that here.

With regards to RAM, no we probably do not need 96GB, however we definitely want all 6 channels propagated so we would be at 24(~$200 retail) or 48GB (about $50 more). Others may want the memory depending on work load, so I will wait to see.

[Mark Rose]

Originally Posted by airsquirrels

I am most likely to purchase the water cooled version and make up the difference myself if needed. I run a lot of systems 24/7 and hands down have much better reliability and easier temperature management, even in cooled racks, using water cooling.

Off topic, but it's worth the expense? I've always seen water cooling as more maintenance heavy that dusting and not as cost effective as buying more hardware when it comes to performance.

With regards to time sharing, I imagined we would have a thread here to informally track reservations. My only request would be that we setup so that when the system is not actively in use for development or test runs we run mprime or similar on it. This could even be automated to run anytime there were no active `screen` sessions or ttys.

Why not just use MaxLoad= and PauseTime= in prime.txt?

I wish I had an actual use for this machine; I would participate if I had.

[ATH]

Originally Posted by ewmayer

On the theme of possibly cutting the dev-system cost: Do we really need that big honking 96GB blob of DDR4 memory? I don't envision doing anything that would need more than 4-5 GB of RAM, which would fit easily in the 16 Gig of fast MCDRAM. What say my fellow would-be KL developers? I mean that DDR4 has gotta run at least $10 a gig, so running without it, or with some lesser 'system minimum' amount (if that is in fact required) could save a nice chunk of money. Similarly, perhaps look at an air-cooled system with just the SSD, i.e. sans the 4TB HD included in Colfax's standard offerings.

We can go with 24 or 48 GB as long as we run 6-channel RAM.

[airsquirrels]

Originally Posted by Mark Rose

Off topic, but it's worth the expense? I've always seen water cooling as more maintenance heavy that dusting and not as cost effective as buying more hardware when it comes to performance.

Why not just use MaxLoad= and PauseTime= in prime.txt?

I wish I had an actual use for this machine; I would participate if I had.

With very performance centric code as a developer I would want to know that my cache wasn't being eaten or cycles used by anything else, even if it was getting out the way. Either way I am sure that is a solvable problem.

I don't believe the water cooling unit was much more expensive based on the other quote I saw. I just hate CPU downclocking due to temps.

[Madpoo]

Originally Posted by GP2

While I have not used it, I think GoFundMe would be a better fit than KickStarter/IndieGogo.

Agreed... the others are more for people interested in funding a new product that they could then purchase. GoFundMe is for whatever...

Ernst mentioned PayPal or check, but not everyone trusts PayPal anymore, and not everyone has a supply of paper checks anymore, not to mention this isn't an option for anyone out of the US (cashing checks from other countries is difficult and costly and mostly impractical).

PS,
Right now the contributors include a small circle of developers who have their own projects that they want to try out, so they are motivated to move forward right away independently of Prime95. But many of us are basically solely interested in Prime95, and it does seem premature at least until the assembly language issues are determined to have been fully resolved and intentions have been clarified. If fundraising mentions Prime95, it creates expectations that development on it is ready to move forward at the present time, and it's just not clear that that's the case.

One thing's for sure though...without access to a Xeon Phi x200 system, no real development could be done. I think there are simulators or whatever that would let you build and test but you'd need some real hardware to run it on for full verification.

But you bring up a good point that maybe it'd be better to do some of the groundwork first like making whatever changes are needed so it would actually build using whatever tools and working out any complications ahead of time.

By then there could be some competition from 3rd party vendors getting their own KNL systems out there (like the SuperMicro setups they've announced). Could be even cheaper by that point... maybe. The biggest cost of a system like that is still going to be the CPU itself though.

[airsquirrels]

Originally Posted by Madpoo

...
One thing's for sure though...without access to a Xeon Phi x200 system, no real development could be done. I think there are simulators or whatever that would let you build and test but you'd need some real hardware to run it on for full verification.

But you bring up a good point that maybe it'd be better to do some of the groundwork first like making whatever changes are needed so it would actually build using whatever tools and working out any complications ahead of time.

By then there could be some competition from 3rd party vendors getting their own KNL systems out there (like the SuperMicro setups they've announced). Could be even cheaper by that point... maybe. The biggest cost of a system like that is still going to be the CPU itself though.

I know the LAG Xeon systems I have built currently cost about the same as the KNL system just barebones without RAM or CPU. While it is true the hardware might eventually become commodity, time is also money. A less capable e5-26xx v2 system two generations old still costs significantly more.

[Madpoo]

Originally Posted by airsquirrels

With regards to time sharing, I imagined we would have a thread here to informally track reservations. My only request would be that we setup so that when the system is not actively in use for development or test runs we run mprime or similar on it. This could even be automated to run anytime there were no active `screen` sessions or ttys.
...
With regards to RAM, no we probably do not need 96GB, however we definitely want all 6 channels propagated so we would be at 24(~$200 retail) or 48GB (about $50 more). Others may want the memory depending on work load, so I will wait to see.

For resource sharing, what's the thought in running VMWare on the bare metal and setting up a few virtual machines running whatever Linux flavor, and some Windows as well (to allow for mprime and Prime95 testing/development).

Perhaps a couple of each, each one allocated 16 processors?

I'm less familiar with VMWare than I am with HyperV, so I'm not entirely sure how VMWare sets machine/core affinity... for purposes of performance it'd be important to NOT allow the hypervisor to shuffle which core is being mapped to a virtual machine. I'm pretty sure it won't do that unless you've over-allocated your cores among all your guests, and if total CPU usage is being maxed out.

Anyway, an arrangement like that would make more memory a better option... at least 48GB, I'd guess (6 x 8GB modules).

[Mark Rose]

KVM would also work and it's free. Docker could also be used since it shares the kernel.

Virtualization will make performance tuning a lot more difficult, since it would be impossible to control what else is running and consuming memory bandwidth for instance.

[tServo]

Originally Posted by Madpoo

For resource sharing, what's the thought in running VMWare on the bare metal and setting up a few virtual machines running whatever Linux flavor, and some Windows as well (to allow for mprime and Prime95 testing/development).
.

I would be utterly astonished if VMware would run on one of these systems,
or any other type of virtualization for that matter.
Just my 2 cents.

[airsquirrels]

Originally Posted by tServo

I would be utterly astonished if VMware would run on one of these systems,
or any other type of virtualization for that matter.
Just my 2 cents.

I believe I read that KNL does not support virtualization instructions.