Forgetting PS4/Xbone and GPU comparisons for a sec, how does the Switch's quad-core ARM Cortex A57 CPU stack up in actual real world, in-game performance versus the CPUs used in Xbox 360, PS3, and Wii U?

above x360, under ps3.
ps3 cpu is still a beast,architecture aside is still above ps4's cpu.

There's no real way to directly compare the Switch CPU with the last-gen consoles, because they use completely different architectures.

However if you're going to try, last-gen CPUs ranked like this PS3 > Xbox 360 > Wii U.

The Wii U's CPU was much weaker than the PS3 and 360, what made it competitive was having a newer architecture and having OoOE, but even then it was still weaker. The Wii U had a 3-core 1.24 GHZ processor, Xbox 360 has a 3-Core / 6 thread 3.2 GHz processor, and PS3 had the Cell which was a completely unique setup best explained as a PPE (aka 1-Core) / 8 SPE (aka 8 super threads) 3.2GHz processor (however, 1 SPE was disabled and another for OS).

The Switch is using a mobile CPU, 4-core ARM Cortex A57 at 1.02 GHz with OoOE. Core for core it should be be in a similar ballpark as the Wii U's Espresso CPU obviously with an additional core to use. It also has more current architecture which helps it even more.

If I were to guess I would say the rankings are like this.

PS3 > Xbox 360 = Switch > Wii U

There are more things we need to know like the Instruction set for all 4, channels, memory bus, and more, but based on what we do know that's my hypothesis.

It is really hard to compare real-world performance for CPU's with such drastically different architectures without benchmarks (and even with benchmarks it is difficult.) 

One way to measure theoretical CPU performance is in DMIPS though (basically how many million instructions per second can the processor perform after considering differences in instruction sets by a generalized benchmark called Dhrystone.) An instruction set is the set of all instructions that the CPU's machine language provides for.

So for the A57 the recorded statistic is 4.1-4.5 DMIPS/MHZ. Let's just take it to be 4.3 DMIPS/MHZ. Mutiply that by a clock speed of 1020 MHZ, and we get 4182 DMIPS/core. 

Scouring the web it looks like Expresso is 2877.32 DMIPS/core  

The ratio of performance is then 4 cores*(4182) DMIPS/core/ 3 cores*(2877.32)DMIPS/core =  1.93 times more instructions/sec for Switch's cpu than Expresso. 

So more or less twice as many instructions per second, on a basic comparison. 

The Xbox 360's CPU provides 5638.90 DMIPS @ 3.2 MHZ for all cores

Which gives a ratio of (4*4182)DMIPS/5638.90 DMIPS or about 3 times the Xenon. 

Not even going to bother comparing to the CELL because the architecture is so odd. 

Jaguar has about 3.6 DMIPS/MHZ , so 1,750 MHZ * 3.6 DMIPS *8 cores = 50,400 DMIPS (for XBOX ONE)

So the Switch's CPU is about a 33% the Jaguar @1,750 MHZ (assuming both use all of their cores.) 

Jaguar in the PS4/XBO ~ 3* A57 in Switch;  A57 in Switch ~ 2*Expresso in Wii U ~ 3*Xenon in Xbox 360 (theoretically; assuming all cores can be used to the max.) 

Performance is of course different, because we know Microsoft and probably Nintendo don't use all of their cores at max. 

Also note that developers have commented that the Xenon has better real-world performance than the Expresso, but that could just be a matter of not bothering with optimization for the Wii U's advantages in ports. 

 

How do you know that?

That is a completly inacurated statement.

Any modern CPU, including Tegra X1, has vast superior features that the CELL couldn´t even dream of.

What a random comment

Could the Switch run GTA5, the PS3 version? That game was gorgeous, not the PS4 version, the PS3 game.

Isn't the 360's CPU just a modified Cell processor? If so what's the difference between them?

On topic IIRC the Wii U CPU are based on the outdated PowerPC 750 chip from 1997 so the PS360 CPUs are way better than the Wii U. As for the Switch it may be clocked lower than the PS360, but it has more feature than the last gen consoles since it was newer so it might be more powerful.

To make it more simple lets say both are competing in a race. The PS360 machine are way faster than the Switch so technically they should win the race. But the Switch still has a chance to be a winner since he know the secret shortcut in the track or can access more powerful item to help him win the race.

In the end its the GPU that dictate console performance since we can see the graphical difference between multiplat games and how that affect framerate. That's the thing that matter the most

GTA5's CPU baseline for the 360, so yes the Switch should be able to.

Kind of. The cores in Xenon were designed originally as the Cell's PPE, and IBM made the Xenon for Microsoft when Microsoft asked for a more powerful CPU than was originally planned. The Cell's PPE is pretty much the same as the cores found in the 360. The cell has 1 PPE (Power Processsor Element) and 8 SPEs (Synegeristic Processor Element). So basically the cell has one general core like the three found in the Xbox 360, and a bunch of synergistic processing elements designed to perform very specific number crunching tasks. The architecture had a lot of bottenecks with respect to memory management though and was a pain to program for. 

Sony's intent was to prevent multiplatform games by having a confusing architecture. Their idea was that if the PS3 just takes off like the PS2 then developers wouldn't want to port games to the 360 because it would be too hard, just like what happened in the PS2/XB era. However, this backfired on Sony big time. 

"On topic since IIRC the Wii U CPU are based on the outdated PowerPC 750 chip from 1997 so the PS360 CPUs are way better than the Wii U."

The CPU was actually updated quite a bit. Expresso has much better IPC than the Xenon and Cell's PPE. The only reason the PS360 outperformed it was because of the raw clock-speed. While it is based on the Gekko, the architecture of the Gekko was actually ahead of its time, and it was updated quite a bit for Expresso. 

For more information see: 

http://www.neogaf.com/forum/showpost.php?p=58036908&postcount=714