Question about having two cpu's

[RadeonProVega]

I'm upgrading my rig soon to a computer that has 2 cpu's slots, and was curious do i have to match up with the same 2 cpus or can you mix them up? (using the same Version , just different processors) I am currenting using a 2678 v3.

 

[newtekie1]

They have to be the same processor.

 

[flatty]

And more than this, would be very nice (to not say highly recommended OR even mandatory in some "picky" motherboards cases) to be "matched pair" (same batch)

 

[Mussels]

I'm upgrading my rig soon to a computer that has 2 cpu's slots, and was curious do i have to match up with the same 2 cpus or can you mix them up? (using the same Version , just different processors) I am currenting using a 2678 v3.

Feels like i havent seen you post in ages, aloha etc

IME, they gotta be matched

 

[Bill_Bright]

RTFM!

 

[flatty]

IME, they gotta be matched

Not mandatory, depend by platform (for example on 1366 ive "matched" without any problem various batch CPUs (ofc, identical), on 2011 and 2011-3 i had problems sometimes. (I couldnt "charge" the mobo in itself or the "platform" (chipset) about this )

 

[mtcn77]

You making a stream pc encoder setup because that is how you make a stream pc encoder setup ?

 

[Bill_Bright]

Seem suggesting, or perhaps it was the way I suggested, you read the manual was considered "Low quality". Not sure why since the acronym has been widely used on this site and across the industry (many industries, actually) for decades. But, if it offended anyone, I apologize. That said, considering the actual language (not acronyms) so often used and allowed on this site, again, not sure why it would offend anyone - but again, I apologize.

Regardless, my advice stands. I would urge you check the user manual for your motherboard. If you don't have it, you typically can download the latest revision from the motherboard's webpage. If not then, then the maker's tech support.

 

[RadeonProVega]

Feels like i havent seen you post in ages, aloha etc

IME, they gotta be matched

Hello. I'm always posting every now and then. Probably post a bit more on guru3d though lately, but I'm still here. Techpowerup is the best forum to get the best advice and quicker responses. Try posting on the AMD forums, you will be waiting for months for a reply lol. I hate that site.

You making a stream pc encoder setup because that is how you make a stream pc encoder setup ?

Gaming, etc. The best desktop i found that has 2x cpu slots is the Dell Precision 7810. I'm using a 5810 right now w/ Intel 2678 v3, w5500 8GB , that would be secondary rig soon(using my wx 7100 with that) once i get the 7810 with 2 decent cpus. w/ my w5500.

 

[mtcn77]

You might need two seperate operating systems because one's dram access will influence the other and you don't want the online computer to stall at the encode latency. Maybe a dual hypervisor dual os setup.
PS: I'm noob, don't be too critical.

 

[Toothless]

Hello. I'm always posting every now and then. Probably post a bit more on guru3d though lately, but I'm still here. Techpowerup is the best forum to get the best advice and quicker responses. Try posting on the AMD forums, you will be waiting for months for a reply lol. I hate that site.


Gaming, etc. The best desktop i found that has 2x cpu slots is the Dell Precision 7810. I'm using a 5810 right now w/ Intel 2678 v3, w5500 8GB , that would be secondary rig soon(using my wx 7100 with that) once i get the 7810 with 2 decent cpus. w/ my w5500.

Got got a buddy that games on a 2687v2 and it's meh. You're better off going at least X79/1680v2 if you want to game on a Xeon. The clockspeeds are the big limiters, not core counts.

Unless you're doing something with multiple game clients, which against nearly all TOS, then sure.

 

[newtekie1]

You might need two seperate operating systems because one's dram access will influence the other and you don't want the online computer to stall at the encode latency. Maybe a dual hypervisor dual os setup.
PS: I'm noob, don't be too critical.

Modern operating systems are Numa node aware. If you run a program that doesn't know how to deal with multiple processors/RAM domains, the Windows is pretty good at keeping that program on one Numa node so it doesn't stall out waiting on communication between nodes.

 

[mtcn77]

Modern operating systems are Numa node aware. If you run a program that doesn't know how to deal with multiple processors/RAM domains, the Windows is pretty good at keeping that program on one Numa node so it doesn't stall out waiting on communication between nodes.

Color me blind, but an operating system keeps the same schedule between different operations and that impacts the latency of real time gaming performance. If you want to keep seperate tabs, you need a whole seperate software chain from the motherboard to the os. However, if you don't care gaming at the encoding latency(I dunno if you are into lag hacking for unfair competitive advantage), you might as well use a single cpu motherboard, threadripper and such.

 

[lexluthermiester]

do i have to match up with the same 2 cpus or can you mix them up?

They have to be the same processor.

This. Additionally it's a good ideal to make sure the CPU model you choose also has matched stepping codes. Having the same CPU model but different steppings can result in system instability that will leave you pulling your hair out in frustration.

 

[Ruru]

Yeah, for the best compatibility and stability, I'd with CPUs which are not just identical, but have the same stepping.

 

[Bill_Bright]

Seems to me, "identical" means just that, "identical". For sure, it is important to ensure the stepping number (or letter, or alpha-numeric version) is the same, but isn't that implied?

I'm just saying, if I see model 2487a, I am not going to assume it is "identical" to 2487b.

 

[Mussels]

Seems to me, "identical" means just that, "identical". For sure, it is important to ensure the stepping number (or letter, or alpha-numeric version) is the same, but isn't that implied?

I'm just saying, if I see model 2487a, I am not going to assume it is "identical" to 2487b.

As an example, back in the days the Q6600 came in G0 and B3 steppings, despite being the same model CPU - and they had differences

 

[Ruru]

As an example, back in the days the Q6600 came in G0 and B3 steppings, despite being the same model CPU - and they had differences

Exactly, for hobbyists, the G0 was a better overclocker. The same happened with Phenom II C2 and C3 steppings.

 

[newtekie1]

Color me blind, but an operating system keeps the same schedule between different operations and that impacts the latency of real time gaming performance. If you want to keep seperate tabs, you need a whole seperate software chain from the motherboard to the os. However, if you don't care gaming at the encoding latency(I dunno if you are into lag hacking for unfair competitive advantage), you might as well use a single cpu motherboard, threadripper and such.

Windows schedules the process for what CPU to use and when. If a program is not Numa node aware, Windows will keep it scheduled on a single CPU/RAM. If you are recording gameplay, it does not matter that the recording process and the game process are on different Numa nodes, this will not add latency. The screen recording is pulling from the VRAM framebuffer, not the game process.

 

[Blue4130]

As an example, back in the days the Q6600 came in G0 and B3 steppings, despite being the same model CPU - and they had differences

Those are not considered identical...

 

[Fouquin]

There's a lot of random tidbits of info being thrown around here that don't answer the question.

Just match the CPU model for both. If you're getting an E5-2687W v4, get two. Don't mix models, and don't worry about matching anything but the model number.

Errata stepping on modern Xeons is uncommon. If Intel has issued a new stepping within the same model it will be specifically listed as such.

 

[lexluthermiester]

Just match the CPU model for both. If you're getting an E5-2687W v4, get two. Don't mix models, and don't worry about matching anything but the model number.

Incorrect. Steppings matter! Always have. Please review;

What numbers must match for a "matched pair" of XEON E5-26xx CPU?

Is it just the stepping number that must match, or does the batch # also have to match? For example, if I have a E5-2670V1 with a stepping of SR0KX and a batch number of 3214D312, do I need to match just the stepping, or do I also have to match the batch number for a matched pair for a dual-CPU...

community.intel.com

Model numbers have to match, stepping codes have to match, batch numbers do NOT.

 

[RadeonProVega]

Got got a buddy that games on a 2687v2 and it's meh. You're better off going at least X79/1680v2 if you want to game on a Xeon. The clockspeeds are the big limiters, not core counts.

Unless you're doing something with multiple game clients, which against nearly all TOS, then sure.

I have a 2678 v3 and i game perfectly fine, 1080p pretty much 50-60fps(97%) in all my games. I have no problems playing any game that's out. So I'm not sure why you say its meh.

 

[Bill_Bright]

As an example, back in the days the Q6600 came in G0 and B3 steppings, despite being the same model CPU - and they had differences

I understand that. And I am not disputing or questioning that. I am just saying that if one is G0 and the other is B3, then clearly they were NOT "identical"! They were very similar, and certainly in the same family, but they were not identical.

If the user did his or her homework - as they should - and thoroughly researched the data, they would have easily seen the difference. And for sure, if someone is building a dual-processor system, they likely are not total noobs - but if they are and don't know enough (or are too egotistical) to research and do their homework first, then they have no business working this project, IMO.

This is nothing new or unique to processors either. For example, when a controller board dies on a hard drive, you cannot just replace the board from any drive from the same maker and model number and expect the drive to work. You have to ensure the revision number is the same too. Or else, you might get a newer one from Taiwan when you really need the older revision that came from Malaysia. Exact same model numbers but NOT "identical".

When looking to flash the BIOS on a motherboard, ensuring the same model number is not good enough. You must ensure you have the right motherboard revision number too. Same model, but not identical.

Steppings matter! Always have.

^^^THIS^^^ And I believe anyone who has built a dual (or quad) processor system should already understand two (or four) processors with the same model number may not be identical.

Way WAY back in the day I was supporting hardware in a major software development company for a big DoD secure network. We were building new quad-core servers with Supermicro boards. We not only had to ensure the processors had the "identical" stepping number, we made sure each set came from the same manufacturing "Lot" number too. Fortunately, these days, motherboards are much more tolerant to slight differences, and processor manufacturers are much better at ensuring consistency and compliance to specs. So ensuring the same lot number is not necessary.

Again, I am just saying, identical means identical - not "almost" the same. And maybe I'm totally wrong, but it is my experience that anyone with experience in this area already knows that. And if new to this area (either professionally or as a hobby enthusiasts), they should know to do the research before spending their $$$, or committing someone else's $$$. That was drilled into me when I first started building dual and quad processor systems. And I drilled that into the junior techs when they started building them.

So back to my original question - isn't it implied that "identical" means the same stepping number too? It does to me.

 

[Toothless]

I have a 2678 v3 and i game perfectly fine, 1080p pretty much 50-60fps(97%) in all my games. I have no problems playing any game that's out. So I'm not sure why you say its meh.

Yes, it does work, but that doesn't always mean it's favorable for that task. If it's not thread limits it's just speed limited. Done those tests on my own Xeon builds and it's the same thing across the board.

Yes it runs, just "good enough" though.