What are the raw performance specs of PSVita?

[Ryan Smith]

Apologies for bumping an old thread, but it didn't make much sense to start a new one.

Thanks to the Vita hackers, we finally know the clockspeeds of the Vita.

Quad Cortex-A9: Default, 333MHz. Range, 41-444MHz
SGX543MP4: Default, 111MHz. Range, 41-222MHz

I knew the Vita was clocked low, but I must admit this comes as quite a surprise. Those are very low default clockspeeds, more than I would have expected even with the need to conserve power.

 

[Deleted member 13524]

GPU clocks are within predicted, since the SGX543MP4 in the A5X released at around the same time clocks at 250MHz.

But those CPU speeds are rather fishy. The guy on twitter refuses to say which game they used for reaching those clocks, claiming it "doesn't matter" because "the kernel doesn't contain games based on what they do", yet he's presenting a varying range of clockspeeds. So which is it?


Web browsing on the Vita certainly doesn't feel like a 444MHz Cortex A9. It feels a lot faster than any Tegra 2 device I've used to date.

 

[Grall]

When you say "default", does this mean that software can bump the CPU/GPU to top speed if they so desire, or would that require rooting the device, or maybe even a hardware modification of some kind?

 

[Shifty Geezer]

Based on what Vita gets on screen, I don't believe those numbers.

 

[Grall]

@Shifty Geezer Why? Numbers too high? Too low?

 

[Nesh]

Isnt 333MHz as much as the PSP's CPU?

 

[Shifty Geezer]

Seem too low. 444 MHz for CPU seems very low for powering a game like Uncharted. Unless the mobile overhead is so significant that Vita's relative performance is far higher.

 

[Arwin]

Mobile overhead *is* huge. Before Metal I think it was 10% or so? As in, 10% performance of what it would have been without hardware abstraction and OS overhead.

 

[Shifty Geezer]

As in the performance extracted from iPad is only 1/10th what's possible without Metal?!

 

[Ryan Smith]

When you say "default", does this mean that software can bump the CPU/GPU to top speed if they so desire, or would that require rooting the device, or maybe even a hardware modification of some kind?

The former seems to be the case judging from the context of the conversation.

 

[Deleted member 13524]

Does anyone know of a browser-based Javascript benchmark with a small footprint?

I've been trying to get my Vita to run one of those for comparison (Octane, Sunspider, etc.) but the console can't finish any of those tests without getting short on RAM.

 

[Deleted member 13524]

Does anyone know of a browser-based Javascript benchmark with a small footprint?

I've been trying to get my Vita to run one of those for comparison (Octane, Sunspider, etc.) but the console can't finish any of those tests without getting short on RAM.

Anyone?

 

[Shifty Geezer]

Maybe ask in a more general computing forum?

 

[Megadrive1988]

Any good estimates for Vita's raw GPU Flops ?

 

[tuna]

Web browsing on the Vita certainly doesn't feel like a 444MHz Cortex A9. It feels a lot faster than any Tegra 2 device I've used to date.

The OS/Browser might be a bit better optimized?

 

[Exophase]

Very sceptical about those CPU speeds. It's possible those refer to some bus speed instead and the actual CPU clock is some multiplier like 2-3x. If anyone has the ability to run homebrew they should run an actual timing loop.

 

[yewyew]

Jeez... if true, that would put the CPU at 3.996GFLOP/s and the GPU at 14.208GFLOP/s.

 

[yewyew]

Very sceptical about those CPU speeds. It's possible those refer to some bus speed instead and the actual CPU clock is some multiplier like 2-3x. If anyone has the ability to run homebrew they should run an actual timing loop.

Just got confirmation it's not FSB.

https://mobile.twitter.com/yewles1/status/645132469008633856?p=v

 

[Exophase]

Just got confirmation it's not FSB.

https://mobile.twitter.com/yewles1/status/645132469008633856?p=v

So "FSB" (I doubt this is a good term for such an SoC but notwithstanding) is 55-222MHz and CPU is 41-444MHz? That's pretty weird.

He made some other comments here, they seem to check out: https://www.reddit.com/r/vita/comments/3hchqr/vita_cpu_clock_speed_is_333_mhz_by_default/

333MHz was measured using cycle counters vs timers. So assuming the cycle counter isn't missing a multiplier (and it shouldn't if it's the standard counter on Cortex-A9) it checks out.

There was a Cortex-A9 SoC out around Vita's time by AFAIK Renesas that also had a very low clock speed, something like 500MHz. Maybe they went with an LP process and just didn't optimize layout for performance at all.

I wonder if - assuming Vita has PSP hardware - the Allegrex clock speed is synchronous with the Cortex-A9 clock speeds.

 

[liolio]

The OS/Browser might be a bit better optimized?

Either way the load is completely different (while browsing the web or using the other utilities the consoles offers) than while gaming, it would not surprise me if the cores are allowed to run way faster when doing so /racing to sleep.
Under gaming circumstances with sustained load for tenth of minutes, etc. the numbers that team announces are not too surprising, we still speak of a 40nm SOC (???) (actually even 14nm Exynos throttles heavily, I know I know different SOC gpu form factor, etc yet).