Yay.. Intel ARK in error... again

[cyberjock]

Here's another ARK error...

https://communities.intel.com/message/288010#288010

 

[Ericloewe]

So... Where the hell are we supposed to get reliable information on Intel products?

At least this case was benign, unlike the ECC Snafu.

 

[Tywin]

I'm not saying it's fun to pull them up when shopping for processors, but the datasheet says this (p14):

- Up to 8 execution cores
- Each core supports two threads (Intel(R) Hyper-Threading Technology), up to 16 threads per socket

 

[marbus90]

Does it say that for the E5-2603? it's a very cheap CPU and supposedly without HT and turboboost. that's for the SKUs starting with x620 and upwards.

 

[Tywin]

The data sheet says "Intel Xeon Processor E5-1600/E5-2600/E5-4600 Product Families - Datasheet Volume One - May 2012"; I was looking for a table detailing the different configurations by product number, but I didn't find anything indicating different HT support. It does say it requires chipset, BIOS, and operating system support, but again, that appears to be for the entire product line.

 

[cyberjock]

I'm not saying it's fun to pull them up when shopping for processors, but the datasheet says this (p14):

Pretty sure that datasheet is not applicable. This is a v2, and it came out in 2013, not 2012 like the datasheet you linked. ;)

 

[Tywin]

Pretty sure that datasheet is not applicable. This is a v2, and it came out in 2013, not 2012 like the datasheet you linked. ;)

Ok, here is the v2 datasheet, published March 2014. It says basically all the same things as that previous datasheet with respect to Hyper-Threading:

• Up to 12 execution cores
• Each core supports two threads (Intel® Hyper-Threading Technology), up to 24 threads per socket

 

[HoneyBadger]

Well, I can't trust the ARK at all, but I'm pretty sure the E5-4627 v2 actually doesn't have HT, so it would run counter to that v2 datasheet.

 

[marbus90]

Ok, here is the v2 datasheet, published March 2014. It says basically all the same things as that previous datasheet with respect to Hyper-Threading:

Not really.

You see, there are more models than just the base Quadcores. There really are 12 core/24 thread CPUs around. The E5-2603 v2 SKU however does NOT feature 24 threads, as well as that SKU doesn't feature Hyperthreading/Turboboost. It only has 4. It goes "up to", not "it is this for every SKU".

With the E5 v3 series you can get 18core/36thread per socket by the way, it boosts to 2.6GHz when all cores are under load. Just doesn't mean that the E5-2603 v3 (1.6GHz 6core) has 36 threads per socket.

 

[Tywin]

Not really.

You see, there are more models than just the base Quadcores. There really are 12 core/24 thread CPUs around. The E5-2603 v2 SKU however does NOT feature 24 threads, as well as that SKU doesn't feature Hyperthreading/Turboboost. It only has 4. It goes "up to", not "it is this for every SKU".

With the E5 v3 series you can get 18core/36thread per socket by the way, it boosts to 2.6GHz when all cores are under load. Just doesn't mean that the E5-2603 v3 (1.6GHz 6core) has 36 threads per socket.

The "up to" you are referring to is talking about number of cores, and everywhere you see "up to m cores" or "up to n threads", n = 2*m. I don't deny that not all products in the family have the same number of cores. None of which changes the other statement from the data sheet: "Each core supports two threads[...]".

I also never claimed the E5-2603 v2 had a different number of cores; this thread is talking about Hyper-Threading.

 

[Ericloewe]

Would you please run the bootable version of Intel® Processor Diagnostic Tool and share a screenshot with the results?

Processors — What is the Intel® Processor Diagnostic Tool?

Anyone else think "Soo... Why doesn't this utility validate ECC?"

 

[anodos]

I think it's funny that Intel has managed to make a hardware product portfolio almost as confusing as a Microsoft software licensing scheme.

 

[marbus90]

The "up to" you are referring to is talking about number of cores, and everywhere you see "up to m cores" or "up to n threads", n = 2*m. I don't deny that not all products in the family have the same number of cores. None of which changes the other statement from the data sheet: "Each core supports two threads[...]".

I also never claimed the E5-2603 v2 had a different number of cores; this thread is talking about Hyper-Threading.

the treads=cores*2 rule only applies to hyperthreading enabled SKUs. I quote: • Each core supports two threads (Intel® Hyper-Threading Technology), up to 24 threads per socket

 

[HoneyBadger]

I'm pretty sure that the E5-4627 v2 actually lacks hyperthreading, so that right there would invalidate the claim that HT is standard across the entire lineup.

Meanwhile in my Opteron cluster, 4-bit ECC is supported.

 

[Tywin]

the treads=cores*2 rule only applies to hyperthreading enabled SKUs. I quote: • Each core supports two threads (Intel® Hyper-Threading Technology), up to 24 threads per socket

I don't understand your point. Yes, the method by which Intel processors are able to execute two threads on each core is called Hyper-Threading. I think we were all in agreement about that. The datasheet says nothing about individual SKUs not supporting Hyper-Threading. It does have a line that says (I'm repeating myself now) that each core supports two threads (and then in brackets it names the mechanism by which two threads are supported on one core). In fact, you quoted this line yourself just now. I'm not saying the datasheet is right, I'm saying that's what the datasheet says.

Edit: Sorry, I'm just trying to be explicit here, so that we aren't talking past each other: the datasheet notably does not say "Each core with Hyper-Threading enabled supports two threads", it just says "each core" period.

I'm pretty sure that the E5-4627 v2 actually lacks hyperthreading, so that right there would invalidate the claim that HT is standard across the entire lineup.

Yeah you noted this above, but left it as a "pretty sure". Can we get the sysctl output, for completeness? Note that I'm not arguing for any particular state of being of the processors. I'm just saying "here's the datasheet, it disagrees with Ark, but agrees with @cyberjock's results". sysctl showing the E5-4627 v2 not having Hyper-Threading would let us say "yeah, the datasheet's garbage too".

 

[marbus90]

The datasheet says "Each core supports two threads (Intel® Hyper-Threading Technology)". But not all SKUs support Hyper-Threading Technology, which means they don't feature 2 threads per core. On page 2 it is said that "Hyper-Threading Technology requires a computer system with a processor supporting HT Technology [...]" as well. Have a look at xeon-e5-v2-spec-update.pdf pages 17ff, where you will find that the specific SKU 2603 v2 is listed with a few notes, the numbers 4 and 5 of which declaring that Hyper-Threading and TurboBoost are not available with these specific SKUs.

 

[DrKK]

This is the most confusing post on the forums for March 2014. Congratulations. ;)

 

[cyberjock]

Thanks! I try my best. ;)

 

[9C1 Newbee]

So there is absolutely no recourse on stuff like this? I mean, could you buy a Xeon processor only to open it up to find a 486 sx and Intel says "Serves you right for paying attention to the ARK"?

I might start using AMD processors. That way you would expect to be disappointed.

 

[anodos]

This is the most confusing post on the forums for March 2014. Congratulations. ;)

I'm still confused about where the big wooden ship full of animals fits in. Or is it an indirect reference to cyberjock's mom? :D