7 ms·

Remains to be seen how the microcode patch affects performance, and how these CPUs that have been affected by over-voltage to the point of instability will have

by tux3 2y ago

Remains to be seen how the microcode patch affects performance, and how these CPUs that have been affected by over-voltage to the point of instability will have aged in 6 months, or a few years from now. More voltage generally improves stability, because there is more slack to close timing. Instability with high voltage suggests dangerous levels. A software patch can lower the voltage from this point on, but it can't take back any accumulated fatigue.

giantg2 2y ago
I was recently looking at building and buying a couple systems. I've always liked Intel. I went AMD this time. It seemed like the base frequencies vs boost frequencies were much farther apart on Intel than with most of the AMDs. This was especially true on the laptops were cooling is a larger concern. So I suspect they were pushing limits. Also, the performance core vs efficiency core stuff seemed kind of gimmicky with so few performance cores and so many efficiency cores. Like look at this 20 core processor! Oh wait, it's really an 8 core when it comes to performance. Hard to compare that to a 12 core 3D cached Ryzen with even higher clock... I will say, it seems intel might still have some advantages. It seems AMD had an issue supporting ECC with the current chipsets. I almost went Intel because of it. I ended up deciding that DDR5 built in error correction was enough for me. The performance graphs also seem to indicate a smoother throughput suggesting more efficient or elegant execution (less blocking?). But on the average the AMDs seem to be putting out similar end results even if the graph is a bit more "spikey".
- nullindividual 2y ago
  > It seems AMD had an issue supporting ECC with the current chipsets. AMD has the advantage with regards to ECC. Intel doesn't support ECC at all on consumer chips, you need to go Xeon. AMD supports it on all chips, but it is up to the motherboard vendor to (correctly) implement. You can get consumer-class AM4/5 boards that have ECC support.
  - jwond 2y ago
    Actually some of the 13th and 14th gen Intel Core processors support ECC.
    - mackal 2y ago
      Intel has always had randomly supported ECC on desktop CPUs. Sometimes it was just a few low end SKUs, sometimes higher end SKUs. 14th gen it appears i9s and i7s do, didn't check i5s, but i3s did not.
  - giantg2 2y ago
    My understanding is that it's screwed up for multiple vendors and chipsets. The boards might say they support it, but there are some updates saying it's not. It seemed extremely hard to find any that actually supported it. It was actually easier to find new Intel boards supporting ECC.
    - paulmd 2y ago
      yeah wendell put out a video a few weeks ago exploring a bunch of problems with asrock rack-branded server-market B650 motherboards and basically the ECC situation was exactly what everyone warns about: the various BIOS versions wandered between "works, but doesn't forward the errors", "doesn't work, and doesn't forward the errors", and (excitingly) "doesn't work and doesn't even post". We are a year and a half after zen4 launched and there barely are any server-branded boards to begin with, and even those boards don't work right. https://youtu.be/RdYToqy05pI?t=503 https://youtu.be/RdYToqy05pI?t=503 I don't know how many times it has to be said but "doesn't explicitly disable" is not the same thing as "support". There are lots of other enablement steps that are required to get ECC to work properly, and they really need to be explicitly tested with each release (which if it is "not explicitly disabled", it's not getting tested). Support means you can complain to someone when it doesn't work right. AMD churns AGESA really, really hard and it breaks all the time. Partners have to try and chase the upstream and sometimes it works and sometimes it doesn't. Elmor (Asus's Bios Guy) talked about this on Overclock.net back around 2017-2018 when AMD was launching X399 and talked about some of the troubles there and with AM4. That said, the current situation has seemingly lit a fire under the board partners, with Intel out of commission and all these customers desperate for an alternative to their W680/raptor lake systems (which do support ecc officially, btw) in these performance-sensitive niches or power-limited datacenter layouts, they are finally cleaning up the mess like, within the last 3 weeks or so. They've very quickly gone from not caring about these boards to seeing a big market opportunity. https://www.youtube.com/watch?v=n1tXJ8HZcj4 https://www.youtube.com/watch?v=n1tXJ8HZcj4 can't believe how many times I've explained in the last month that yes, people do actually run 13700Ks in the datacenter... with ECC... and actually it's probably some pretty big names in fact. A previous video dropped the tidbit that one of the major affected customers is Citadel Capital - and yeah, those are the guys who used to get special EVEREST and BLACK OPS skus from intel for the same thing. Client platform is better at that, the very best sapphire rapids or epyc -F or -X3D sku is going to be like 75% of the performance at best. It's also the fastest thing available for serving NVMe flash storage (and Intel specifically targeted this, the Xeon E-2400 series with the C266 chipset can talk NVMe SAS natively on its chipset with up to 4 slimsas ports...) it's somewhere in this one I think: https://www.youtube.com/watch?v=5KHCLBqRrnY https://www.youtube.com/watch?v=5KHCLBqRrnY
- fomine3 2y ago
  More E-core is reasonable for multi threaded application performance. It's efficient for power and die area as the name indicates, so they can implement more E-cores than P-cores for the same power/area budget. It's not suitable for who need many single threaded performance cores like VM server, but I don't know is there any major consumer usage requires such performance.
  - giantg2 2y ago
    I can sort of see that. The way I saw it explained as them being much lower clock and having a pretty small shared cache. I could see E cores as being great for running background processes and stuff. All the benchmarks seem to show the AMDs with 2/3rd the cores being around the same performance and with similar power draw. I'm not putting them down. I'm just saying it seems gimmicky to say "look at our 20 core!" with the implicit idea that people will compare that with an AMD 12 core seeing 20>12, but not seeing the other factors like cost and benchmarks.
    - philistine 2y ago
      It's the megahertz wars all over again!
      - cyanydeez 2y ago
        Computers have taught is the rubric of truth: Numbers go Up.
  - Sohcahtoa82 2y ago
    > but I don't know is there any major consumer usage requires such performance. Gaming. There are some games that will benefit from greater single-core performance.
    - deleted 2y ago
      [deleted]
- akira2501 2y ago
  > so few performance cores and so many efficiency cores I was baffled by this too but what they don't make clear is the performance cores have hyperthreading the efficiency cores do not. So what they call 2P+4E actually becomes an 8 core system as far as something like /proc/cpuinfo is concerned. They're also the same architecture so code compiled for a particular architecture will run on either core set and can be moved from one to the other as the scheduler dictates.
  - Dylan16807 2y ago
    > They're also the same architecture so code compiled for a particular architecture will run on either core set and can be moved from one to the other as the scheduler dictates. I don't know if that has done more good than harm, since they ripped AVX-512 out for multiple generations to ensure parity.
- Dylan16807 2y ago
  > Like look at this 20 core processor! Oh wait, it's really an 8 core when it comes to performance. The E cores are about half as fast as the P cores depending on use case, at about 30% of the size. If you have a program that can use more than 8 cores, then that 8P+12E CPU should approach a 14P CPU in speed. (And if it can't use more than 8 cores then P versus E doesn't matter.) (Or if you meant 4P+16E then I don't think those exist.) > Hard to compare that to a 12 core 3D cached Ryzen with even higher clock... Only half of those cores properly get the advantage of the 3D cache. And I doubt those cores have a higher clock. AMD's doing quite well but I think you're exaggerating a good bit.
  - ComputerGuru 2y ago
    > If you have a program that can use more than 8 cores, then that 8P+12E CPU should approach a 14P CPU in speed Only if you use work stealing queues or (this is ridiculously unlikely) run multithreaded algorithms that are aware of the different performance and split the work unevenly to compensate.
    - Dylan16807 2y ago
      Or if you use a single queue... which I would expect to be the default. Blindly dividing work units across cores sounds like a terrible strategy for a general program that's sharing those cores with who-knows-what.
      - ComputerGuru 2y ago
        It’s a common strategy for small tasks where the overhead of dispatching the task greatly exceeds the computation of it. It’s also a better way to maximize L1/L2 cache hit rates by improving memory locality. Eg you have 100M rows and you want to cluster them by a distance function (naively), running dist(arr[i], arr[j]) is crazy fast, the problem is just that you have so many of them. It is faster to run it on one core than dispatch it from one queue to multiple cores, but best to assign the work ahead of time to n cores and have them crunch the numbers.
- jiggawatts 2y ago
  A major differentiator is that Intel CPUs with E cores don’t allow the use of AVX-512, but all current AMD CPUs do. The new Zen 5 chips will run circles around Intel for any such workload. Video encoding, 3D rendering, and AI come to mind. For developers: many database engines can use AVX-512 automatically.
paulmd 2y ago
> Remains to be seen how the microcode patch affects performance intel is claiming 4% performance hit on the final patch https://youtu.be/wkrOYfmXhIc?t=308 https://youtu.be/wkrOYfmXhIc?t=308
oasisbob 2y ago
Maybe a stretch - but this reminds me of blood sugar regulation for people with type 1 diabetes. Too low is dangerous because you lose rational thought, and the ability to maintain consciousness or self-recover. However, despite not having the immediate dangers of being low, having high blood sugar over time is the condition which causes long-term organ damage.

by tux3 2y ago

giantg2 2y ago

I was recently looking at building and buying a couple systems. I've always liked Intel. I went AMD this time. It seemed like the base frequencies vs boost frequencies were much farther apart on Intel than with most of the AMDs. This was especially true on the laptops were cooling is a larger concern. So I suspect they were pushing limits. Also, the performance core vs efficiency core stuff seemed kind of gimmicky with so few performance cores and so many efficiency cores. Like look at this 20 core processor! Oh wait, it's really an 8 core when it comes to performance. Hard to compare that to a 12 core 3D cached Ryzen with even higher clock... I will say, it seems intel might still have some advantages. It seems AMD had an issue supporting ECC with the current chipsets. I almost went Intel because of it. I ended up deciding that DDR5 built in error correction was enough for me. The performance graphs also seem to indicate a smoother throughput suggesting more efficient or elegant execution (less blocking?). But on the average the AMDs seem to be putting out similar end results even if the graph is a bit more "spikey".

nullindividual 2y ago
> It seems AMD had an issue supporting ECC with the current chipsets. AMD has the advantage with regards to ECC. Intel doesn't support ECC at all on consumer chips, you need to go Xeon. AMD supports it on all chips, but it is up to the motherboard vendor to (correctly) implement. You can get consumer-class AM4/5 boards that have ECC support.
- jwond 2y ago
  Actually some of the 13th and 14th gen Intel Core processors support ECC.
  - mackal 2y ago
    Intel has always had randomly supported ECC on desktop CPUs. Sometimes it was just a few low end SKUs, sometimes higher end SKUs. 14th gen it appears i9s and i7s do, didn't check i5s, but i3s did not.
- giantg2 2y ago
  My understanding is that it's screwed up for multiple vendors and chipsets. The boards might say they support it, but there are some updates saying it's not. It seemed extremely hard to find any that actually supported it. It was actually easier to find new Intel boards supporting ECC.
  - paulmd 2y ago
    yeah wendell put out a video a few weeks ago exploring a bunch of problems with asrock rack-branded server-market B650 motherboards and basically the ECC situation was exactly what everyone warns about: the various BIOS versions wandered between "works, but doesn't forward the errors", "doesn't work, and doesn't forward the errors", and (excitingly) "doesn't work and doesn't even post". We are a year and a half after zen4 launched and there barely are any server-branded boards to begin with, and even those boards don't work right. https://youtu.be/RdYToqy05pI?t=503 https://youtu.be/RdYToqy05pI?t=503 I don't know how many times it has to be said but "doesn't explicitly disable" is not the same thing as "support". There are lots of other enablement steps that are required to get ECC to work properly, and they really need to be explicitly tested with each release (which if it is "not explicitly disabled", it's not getting tested). Support means you can complain to someone when it doesn't work right. AMD churns AGESA really, really hard and it breaks all the time. Partners have to try and chase the upstream and sometimes it works and sometimes it doesn't. Elmor (Asus's Bios Guy) talked about this on Overclock.net back around 2017-2018 when AMD was launching X399 and talked about some of the troubles there and with AM4. That said, the current situation has seemingly lit a fire under the board partners, with Intel out of commission and all these customers desperate for an alternative to their W680/raptor lake systems (which do support ecc officially, btw) in these performance-sensitive niches or power-limited datacenter layouts, they are finally cleaning up the mess like, within the last 3 weeks or so. They've very quickly gone from not caring about these boards to seeing a big market opportunity. https://www.youtube.com/watch?v=n1tXJ8HZcj4 https://www.youtube.com/watch?v=n1tXJ8HZcj4 can't believe how many times I've explained in the last month that yes, people do actually run 13700Ks in the datacenter... with ECC... and actually it's probably some pretty big names in fact. A previous video dropped the tidbit that one of the major affected customers is Citadel Capital - and yeah, those are the guys who used to get special EVEREST and BLACK OPS skus from intel for the same thing. Client platform is better at that, the very best sapphire rapids or epyc -F or -X3D sku is going to be like 75% of the performance at best. It's also the fastest thing available for serving NVMe flash storage (and Intel specifically targeted this, the Xeon E-2400 series with the C266 chipset can talk NVMe SAS natively on its chipset with up to 4 slimsas ports...) it's somewhere in this one I think: https://www.youtube.com/watch?v=5KHCLBqRrnY https://www.youtube.com/watch?v=5KHCLBqRrnY
fomine3 2y ago
More E-core is reasonable for multi threaded application performance. It's efficient for power and die area as the name indicates, so they can implement more E-cores than P-cores for the same power/area budget. It's not suitable for who need many single threaded performance cores like VM server, but I don't know is there any major consumer usage requires such performance.
- giantg2 2y ago
  I can sort of see that. The way I saw it explained as them being much lower clock and having a pretty small shared cache. I could see E cores as being great for running background processes and stuff. All the benchmarks seem to show the AMDs with 2/3rd the cores being around the same performance and with similar power draw. I'm not putting them down. I'm just saying it seems gimmicky to say "look at our 20 core!" with the implicit idea that people will compare that with an AMD 12 core seeing 20>12, but not seeing the other factors like cost and benchmarks.
  - philistine 2y ago
    It's the megahertz wars all over again!
    - cyanydeez 2y ago
      Computers have taught is the rubric of truth: Numbers go Up.
- Sohcahtoa82 2y ago
  > but I don't know is there any major consumer usage requires such performance. Gaming. There are some games that will benefit from greater single-core performance.
  - deleted 2y ago
    [deleted]
akira2501 2y ago
> so few performance cores and so many efficiency cores I was baffled by this too but what they don't make clear is the performance cores have hyperthreading the efficiency cores do not. So what they call 2P+4E actually becomes an 8 core system as far as something like /proc/cpuinfo is concerned. They're also the same architecture so code compiled for a particular architecture will run on either core set and can be moved from one to the other as the scheduler dictates.
- Dylan16807 2y ago
  > They're also the same architecture so code compiled for a particular architecture will run on either core set and can be moved from one to the other as the scheduler dictates. I don't know if that has done more good than harm, since they ripped AVX-512 out for multiple generations to ensure parity.
Dylan16807 2y ago
> Like look at this 20 core processor! Oh wait, it's really an 8 core when it comes to performance. The E cores are about half as fast as the P cores depending on use case, at about 30% of the size. If you have a program that can use more than 8 cores, then that 8P+12E CPU should approach a 14P CPU in speed. (And if it can't use more than 8 cores then P versus E doesn't matter.) (Or if you meant 4P+16E then I don't think those exist.) > Hard to compare that to a 12 core 3D cached Ryzen with even higher clock... Only half of those cores properly get the advantage of the 3D cache. And I doubt those cores have a higher clock. AMD's doing quite well but I think you're exaggerating a good bit.
- ComputerGuru 2y ago
  > If you have a program that can use more than 8 cores, then that 8P+12E CPU should approach a 14P CPU in speed Only if you use work stealing queues or (this is ridiculously unlikely) run multithreaded algorithms that are aware of the different performance and split the work unevenly to compensate.
  - Dylan16807 2y ago
    Or if you use a single queue... which I would expect to be the default. Blindly dividing work units across cores sounds like a terrible strategy for a general program that's sharing those cores with who-knows-what.
    - ComputerGuru 2y ago
      It’s a common strategy for small tasks where the overhead of dispatching the task greatly exceeds the computation of it. It’s also a better way to maximize L1/L2 cache hit rates by improving memory locality. Eg you have 100M rows and you want to cluster them by a distance function (naively), running dist(arr[i], arr[j]) is crazy fast, the problem is just that you have so many of them. It is faster to run it on one core than dispatch it from one queue to multiple cores, but best to assign the work ahead of time to n cores and have them crunch the numbers.
jiggawatts 2y ago
A major differentiator is that Intel CPUs with E cores don’t allow the use of AVX-512, but all current AMD CPUs do. The new Zen 5 chips will run circles around Intel for any such workload. Video encoding, 3D rendering, and AI come to mind. For developers: many database engines can use AVX-512 automatically.

paulmd 2y ago

> Remains to be seen how the microcode patch affects performance intel is claiming 4% performance hit on the final patch https://youtu.be/wkrOYfmXhIc?t=308 https://youtu.be/wkrOYfmXhIc?t=308

oasisbob 2y ago

Maybe a stretch - but this reminds me of blood sugar regulation for people with type 1 diabetes. Too low is dangerous because you lose rational thought, and the ability to maintain consciousness or self-recover. However, despite not having the immediate dangers of being low, having high blood sugar over time is the condition which causes long-term organ damage.