Discussion ARM Cortex/Neoverse IP + SoCs (no custom cores) Discussion

[soresu]

Consumer POV.
You're not the person ROCm is for (for now, anyway).

I wasn't referring to myself.

 

[hemedans]

This ☝️

Apple's "little" cores have been more equivalent to A7x/7xx for many generations now, and from what I can tell Qualcomm small/little cores are just the big ones with stuff taken out to cut on area, sort of like the difference between A78 and X1 working from the same foundation, just with more/wider silicon in the case of X1.

ARM Ltd have been steadily increasing IPC of A7xx/Cx Pro for several generations now, but it seems that perf/watt has been their prime focus above all else as efficiency gains are usually the touted metric.

No they don't, it's like they abandon them, A78 was released 2020 and 5 years later C1 pro is marginal better than A78.

 

[soresu]

and 5 years later C1 pro is marginal better than A78

They haven't increased IPC as fast as the X/Ultra cores, but they weren't meant to as A77 was the last big A core really punching big.

As to the A78 -> C1 Pro IPC gain it is definitely not marginal.

I worked out the gain from A76 -> A720 to be roughly 1.81x back in December 2024, though that's missing the A725 + C1 Pro data and adding the A77 (1.2x) + A78 (1.07-1.09x?) gain.

Apart from various other things in the post A78 µArchs A715 turned up the gas for a 5 wide core, which I don't think they have widened further since.

My brain isn't mathing well this late in the day to take out the A77/A78 figures, and I don't have the A725 IPC figures yet, so if someone wants to enlighten me please do.

 

[DZero]

They haven't increased IPC as fast as the X/Ultra cores, but they weren't meant to as A77 was the last big A core really punching big.

As to the A78 -> C1 Pro IPC gain it is definitely not marginal.

I worked out the gain from A76 -> A720 to be roughly 1.81x back in December 2024, though that's missing the A725 + C1 Pro data and adding the A77 (1.2x) + A78 (1.07-1.09x?) gain.

Apart from various other things in the post A78 µArchs A715 turned up the gas for a 5 wide core, which I don't think they have widened further since.

My brain isn't mathing well this late in the day to take out the A77/A78 figures, and I don't have the A725 IPC figures yet, so if someone wants to enlighten me please do.

Seems that the C1 Pro is being targeted to be the next "Small/middle core" and this is why the performance gains are not noticeable. However the consumption is another story.

 

[hemedans]

They haven't increased IPC as fast as the X/Ultra cores, but they weren't meant to as A77 was the last big A core really punching big.

As to the A78 -> C1 Pro IPC gain it is definitely not marginal.

I worked out the gain from A76 -> A720 to be roughly 1.81x back in December 2024, though that's missing the A725 + C1 Pro data and adding the A77 (1.2x) + A78 (1.07-1.09x?) gain.

Apart from various other things in the post A78 µArchs A715 turned up the gas for a 5 wide core, which I don't think they have widened further since.

My brain isn't mathing well this late in the day to take out the A77/A78 figures, and I don't have the A725 IPC figures yet, so if someone wants to enlighten me please do.

according to Arm A720 is 10% faster than A78 at same area usage.

you can even check real life scores, botth dimensity 7300 and snapdragon 7s gen 3 has same frequency, one use A78 and other A720, difference in geekbecnh single core is around 10%.

Snapdragon 7s Gen 3 vs Dimensity 7300: tests and benchmarks

We put Qualcomm Snapdragon 7s Gen 3 against MediaTek Dimensity 7300 to find out which SoC is better. See performance comparison in benchmarks and...

nanoreview.net

 

[soresu]

according to Arm A720 is 10% faster than A78 at same area usage.

OK now you just jumped to a totally different metric.

I was initially talking about perf/watt first, and then refuting your point about A78 -> C1 Pro being marginal in the assumption that you were talking IPC.

Also that A720 = 10% better IPC at ISO area claim was for an area optimised variant of A720, and not the µArchs base IPC....

 

[soresu]

Ah the full slide....

 

[soresu]

Seems that the C1 Pro is being targeted to be the next "Small/middle core"

The segment has been that since at least 2-3 generations ago, reflected in both changing ARM PR and which cores OEMs like Mediatek put in their high end SoCs.

 

[DZero]

The segment has been that since at least 2-3 generations ago, reflected in both changing ARM PR and which cores OEMs like Mediatek put in their high end SoCs.

And also mid high end like the D8400.
Expecting next year an Hexa Big core on the D7500 since SD 7 Gen 4 and Exynos 1680 goes Penta core.

 

[hemedans]

OK now you just jumped to a totally different metric.

I was initially talking about perf/watt first, and then refuting your point about A78 -> C1 Pro being marginal in the assumption that you were talking IPC.

Also that A720 = 10% better IPC at ISO area claim was for an area optimised variant of A720, and not the µArchs base IPC....

View attachment 130846

What about geekbench? Same node same frequency difference was 11% there.