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2012 iMac with I7 shows only ONE core in Activity Monitor

S

SDDave2007

macrumors regular
Original poster
Apr 12, 2007
197
1
Should I not be seeing FOUR Cpu graphs?

I see TWO on my 13" MacBookPro, and saw FOUR on my MacPro tower

Why do I only see ONE on this iMac??????
 
SDDave2007 said:
Should I not be seeing FOUR Cpu graphs?

I see TWO on my 13" MacBookPro, and saw FOUR on my MacPro tower

Why do I only see ONE on this iMac??????
Click to expand...

It's because the computer has 4 cores and 8 threads, which are like virtual cores. This means that your computer has 4 physical and 4 virtual cores (1 physical and 1 virtual for each core). This gives you a total of 8 cores. Instead of showing 8 separate cores as it will if you ctrl+click on the icon, select monitors, and then choose either "show CPU usage" or either of the floating windows, it just combines it into one window for simplicity. Hope this helps!
 
WilliamG said:
No you shouldn't. This was the same on my old quad-core i7 2009 iMac, and it's the same on my new 2012 quad. It's just the way it's displayed.
Click to expand...

Must be it's a quad core then, on my base 2012 mini I see 4 in AM.
 

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I've always wondered this as well.

I have a 2011 iMac with a quad-core i7, that's 4 physical processor cores on a single dye. Therefore, 4 cores should show up in Activity Monitor. However, that is not the case. Instead, I see a single processor core.

I have seen Macs with a dual-core processor, 2 physical processor cores on a single dye, show 2 cores in Activity Monitor. These were MacBooks, MacBook Pros, and older iMacs.

Does Apple install different versions of Activity Monitor on different machines or something else?

Ironically, I have three different apps on my Mac that recognize my machine having 4 cores, as well as other system specs. They are: System Profiler, iStat, and Adobe Photoshop. And iStat shows any activity that is going on with my processor. So what's the deal?
 
SoAnyway said:
Sort of answers what I was asking but I was referring to the post above mine where you see each core in the main Activity Monitor window.
Click to expand...

Per the Apple article, if 4 cores or less, it shows all cores. If more, it consolidates them into a single display. Additionally, if Hyperthreading is present, they are also counted into the "cores" count. Bottom line, if your computer has 4 (or fewer) cores, real or virtual, you'll see 4 CPU usage graphs. If your computer has more than 4 cores (real or virtual) it will show a single CPU graph - that's how an i7 with Hyperthreading will be displayed. I just verified this behavior with my iMac with an i7 - 1 CPU graph (8 virtual cores) while my MBP w/Core 2Duo shows 2 CPU graphs (2 cores).
 
Nuke61 said:
Per the Apple article, if 4 cores or less, it shows all cores. If more, it consolidates them into a single display. Additionally, if Hyperthreading is present, they are also counted into the "cores" count. Bottom line, if your computer has 4 (or fewer) cores, real or virtual, you'll see 4 CPU usage graphs. If your computer has more than 4 cores (real or virtual) it will show a single CPU graph - that's how an i7 with Hyperthreading will be displayed. I just verified this behavior with my iMac with an i7 - 1 CPU graph (8 virtual cores) while my MBP w/Core 2Duo shows 2 CPU graphs (2 cores).
Click to expand...

You are correct. Hyperthreading only became available with the "core i-x" series chips. The Core 2 Duo's and before did not have this technology. As an example, this would mean that a DC (Dual Core) C2D would register 2 cores, a DC i5 4 cores, and a QC i7 8 cores. Hope this breakdown helps!
 
Nuke61 said:
Per the Apple article, if 4 cores or less, it shows all cores. If more, it consolidates them into a single display. Additionally, if Hyperthreading is present, they are also counted into the "cores" count. Bottom line, if your computer has 4 (or fewer) cores, real or virtual, you'll see 4 CPU usage graphs. If your computer has more than 4 cores (real or virtual) it will show a single CPU graph - that's how an i7 with Hyperthreading will be displayed. I just verified this behavior with my iMac with an i7 - 1 CPU graph (8 virtual cores) while my MBP w/Core 2Duo shows 2 CPU graphs (2 cores).
Click to expand...

Rokeneer said:
You are correct. Hyperthreading only became available with the "core i-x" series chips. The Core 2 Duo's and before did not have this technology. As an example, this would mean that a DC (Dual Core) C2D would register 2 cores, a DC i5 4 cores, and a QC i7 8 cores. Hope this breakdown helps!
Click to expand...


Thanks for breaking that down, I was reading the article with my sort-of legalese glasses on and forgot to factor in hypterthreading as 2 cores.

Got it, thanks guys!
 
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