MP 7,1 Question about CPU upgrade (Xeon W3275M)

[sirio76]

Hi everyone,
I'm about to upgrade the CPU on my 2019 Mac Pro, I found a brand new Xeon W3275M for a good price, the specification seems correct.
My only doubt regard the stepping B1 in the description, I just want to be sure that stepping B1 are the correct version to get.
Thanks

 

[cobra521]

Sirio,

I bought one from eBay. Not sure about what is called what: on mine, CPU-Z reports the stepping as "7" and the Revision as "B1/L1"

Here's the CPU-Z output from that chip after I installed it in the 7,1:

Tom

 

[sirio76]

Sirio,

I bought one from eBay. Not sure about what is called what: on mine, CPU-Z reports the stepping as "7" and the Revision as "B1/L1"

Here's the CPU-Z output from that chip after I installed it in the 7,1:
View attachment 970439

Tom

Thanks for the info, is it running fine?

 

[cobra521]

Sirio,

It seems to be OK. I am planning to resilver it, as I have had its temperature creep up from the mid 40s (C) to the low 50s.

I will get some fresh Arctic Silver and do that probably next week.

Tightening the heat sink screws seems touchy. I had a few freezes at first until I evened up the screw tensions - no problems in the months since then except for the above temperature creep.

Tom

 

[SecuritySteve]

Your CPU-Z screenshot shows you are getting 6 cores with 6 threads ... but that should be a 28 core chip. Is that just CPU-Z misreporting or are you actually only getting 6 cores?

 

[cobra521]

Steve,

CPU-Z is running under VMWare Fusion so I think that may be an artifact of how many cores may be allocated to it.

The "About This Mac" reports Processor: 2.5 GHz 28-Core Intel Xeon W

Tom

 

[SecuritySteve]

That makes much more sense!

 

[sirio76]

Steve,

CPU-Z is running under VMWare Fusion so I think that may be an artifact of how many cores may be allocated to it.

The "About This Mac" reports Processor: 2.5 GHz 28-Core Intel Xeon W

Tom

To be sure you can run the Intel power gadget, then you check if every core is running at full speed. Under full load it should reach 3.2ghz on all the 28core, singe core speed should be about 4.4ghz.

 

[cobra521]

Sirio,

I ran the Intel Power Gadget and proved I didn't really know what I was seeing!

I ran the "All Thread Frequency" and it showed the core max at 3.2, and the core avg at 3.17. Single core reported 4.4

Not sure how to see 28 cores with that software. Can you illuminate?

Tom

 

[grunty]

Steve,

CPU-Z is running under VMWare Fusion so I think that may be an artifact of how many cores may be allocated to it.

The "About This Mac" reports Processor: 2.5 GHz 28-Core Intel Xeon W

Tom

sysctl -a | grep machdep.cpu

will give you the same info as CPU-Z but from the mac itself rather than the Virtual Machine

 

[cobra521]

grunty,

Thank you.

Here's a trimmed down version of the output from your suggested command:

sysctl -a | grep machdep.cpu

machdep.cpu.vendor: GenuineIntel
machdep.cpu.brand_string: Intel(R) Xeon(R) W-3275M CPU @ 2.50GHz
machdep.cpu.family: 6
machdep.cpu.model: 85
machdep.cpu.extmodel: 5
machdep.cpu.extfamily: 0
machdep.cpu.stepping: 7
.
.
.
machdep.cpu.core_count: 28
machdep.cpu.thread_count: 56

The result looks the same as CPU-Z as you predicted.

Tom