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Ascn

macrumors newbie
Original poster
May 10, 2020
25
10
Hey there,

it looks like the M3 Pro has only 150GB/s memory bandwith compared to 200GB/s of M1 Pro and M2 Pro.
Why do you think that they lowered this? Is there any information on the type of memory used?

Best,

Andreas
 

LinkRS

macrumors 6502
Oct 16, 2014
402
331
Texas, USA
The vanilla M? series SOC's always have less bandwidth than the Pro, Max, and Ultra SOCs. The M3 > M2 > M1. You need to compare the M3 Pro > M2 Pro > M1 Pro, etc.... Hope this helps :)

Rich S.

Update: Info is not relevant to OP's post. Sorry :-(

Let's make this post useful. Looking at the 'offical' specs page here: https://www.apple.com/macbook-pro/specs/

You can see that the M3 Pro only has the previously mentioned 150GBs of bandwidth, and even the 14" with the binned Max option only has 300GBs. However, if you click on the 16" option on that page, and check the 16" with the full Max configuration (16 Core CPU and 40 Core GPU), it has the expected 400GBs. Looks like Apple is cost cutting on the lower-tiered SOCs. What is going to be interesting, is how this impacts GPU performance. Maybe Apple discovered that in the lower configurations, the extra 50 GB/s of bandwidth wasn't utilized, and reduced it for cost reasons?
 
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AeroHydra

macrumors newbie
Oct 30, 2023
11
13
The vanilla M? series SOC's always have less bandwidth than the Pro, Max, and Ultra SOCs. The M3 > M2 > M1. You need to compare the M3 Pro > M2 Pro > M1 Pro, etc.... Hope this helps :)

Rich S.
Apparently the M3 Pro has less bandwidth than the M2 Pro. Same with M3 Max vs M2 Max. We are comparing within classes here (150 GB/s vs 200 and 300 vs 400)
 

SpotOnT

macrumors 6502a
Dec 7, 2016
925
1,964
I was surprised by this too.

Would be really interesting to know what the 25% decreases in memory bandwidth vs last gen.
 

canadianreader

macrumors 65816
Sep 24, 2014
1,156
3,193
This post sums it up perfectly


Screenshot.jpg
 

canadianreader

macrumors 65816
Sep 24, 2014
1,156
3,193
And here I thought the M3 was going to be the chip to get. I hope this recent Qualcomm chip announcement lights a fire under Apple's ass so that the M4 is worthwhile.
This keynote's target audience is M1 and Intel iMac owners they kept comparing the new chip performance to M1 they know M2 users won't be upgrading for at least another 2 product cycles M4 or M5.
 
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mike...

macrumors 6502
Oct 9, 2008
382
967
In the keynote Apple said M3 Pro has a 20% CPU performance improvement over M1 Pro. The M2 Pro also had a 20% performance improvement over M1 Pro. For M3, and M3 Max Apple provided a comparison with the equivalent M2, but not for M3 Pro. It seems M3 Pro has no CPU performance improvements over M2 Pro, presumably because of the change to 6+6 cores.
 

Pezimak

macrumors 68040
May 1, 2021
3,242
3,601
Apparently the M3 Pro has less bandwidth than the M2 Pro. Same with M3 Max vs M2 Max. We are comparing within classes here (150 GB/s vs 200 and 300 vs 400)

Well that’s interesting. Didn’t know they cut back on the Max too. Real world comparisons will be interesting, but the GOU in the M3 is a lot more powerful and advanced, maybe with its extra built in hardware acceleration it doesn’t need as fast a memory bus to move the data. tween CPU and GPU? If that’s how it works?
 

mike...

macrumors 6502
Oct 9, 2008
382
967
Well that’s interesting. Didn’t know they cut back on the Max too. Real world comparisons will be interesting, but the GOU in the M3 is a lot more powerful and advanced, maybe with its extra built in hardware acceleration it doesn’t need as fast a memory bus to move the data. tween CPU and GPU? If that’s how it works?

The memory bus is where data is moved, although not between CPU and GPU as with unified memory they each have direct access to whatever is in memory. Performance may not take a hit thanks to dynamic caching which could reduce the amount of data that's needed to be moved.
 
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SpotOnT

macrumors 6502a
Dec 7, 2016
925
1,964
In the keynote Apple said M3 Pro has a 20% CPU performance improvement over M1 Pro. The M2 Pro also had a 20% performance improvement over M1 Pro. For M3, and M3 Max Apple provided a comparison with the equivalent M2, but not for M3 Pro. It seems M3 Pro has no CPU performance improvements over M2 Pro, presumably because of the change to 6+6 cores.

Really feels like they intentionally downgraded the Pro chip to drive people to get the Max chip.

Apples recent tendency to intentionally cripple performance to create product segmentation really bother me.

Things were so clear with the M1 and M2. If you needed a better GPU, you went with Max. If not you go Pro. Now it is all a mess.

People who need a better CPU don’t necessarily always need a better GPU.
 
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deaglecat

macrumors 6502a
Mar 9, 2012
609
731
...with Apple nowadays, there seems to always now be one thing that goes backwards - whether it is cooling, memory chips etc

almost like they purposefully have a special department to put these backwards steps in.
 
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Pezimak

macrumors 68040
May 1, 2021
3,242
3,601
The memory bus is where data is moved, although not between CPU and GPU as with unified memory they each have direct access to whatever is in memory. Performance may not take a hit thanks to dynamic caching which could reduce the amount of data that's needed to be moved.

Thanks, that is what I was thinking of was caching. Guess the only way to know is to see real world comparisons.
 

satchmo

macrumors 603
Aug 6, 2008
5,099
5,831
Canada
The 14" M2 Pro 16/512 perhaps is the better buy at $500 less than the M3 18/512 at Apple's refurbished site.
 

rick3000

macrumors 6502a
May 6, 2008
647
273
West Coast
I'm willing to wait for actual testing on this, while I haven't been too happy about Apple taking steps backward with "upgrades" it may not be as big a deal in real world testing as on paper.
 
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