7940HS vs 7840U - PS3 emulation performance?

Hi everyone,

I see that the new Framework 16 has a 7940HS CPU compared to 7840U on the Framework 13.

I have a Framework 13 on pre-order. (My first Framework ever).

I intend to use this laptop primarily for PS3 emulation using RPCS3.

I am wondering how big the performance difference is between these two CPUs on RPCS3? Could anyone give me an idea?

If it is a big difference, I may get the Framework 16 instead.

I appreciate any information anyone can provide! Thanks!

Some quick googling tells me that the performance is nearly identical between the two. Idk if that’s right, but 3 generic benchmark sites said the same thing.

That’s what it seemed like to me too, but seems off since the wattage difference between the two is so large? Plus RPCS3 is weird in how it performs with different hardware. I know they both have AVX 512 though.

I think emulation is much more dependent on the instruction sets available and less on raw performance/frequency, so since these processors are the same architecture mostly, there’s not really a difference. Some things just don’t scale with power. Take this with a grain of salt though, I haven’t used my FW to emulate.

I wish they offered the 7840U as an option for the FW 16 (ordered my FW 16 earlier today), I’m interested in the potential power savings.

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The HS and U series chips are the exact same silicon, the performance between the two will be almost entirely down to the difference in wattage. They are both “Phoenix” chips which is the internal codename for the design.

The U series chips are one which have been selected to have lower leakage, which means less wasted current. Lower leakage chips use less power overall, but do not clock as high or scale as well with voltage. Therefore the U series chips will have a different Voltage/Frequency scaling curve applied from the factory in order to optimise them for running at 15w.

The HS series chips are one which scale better with voltage and have a different V/F curve designed for the higher power they will receive from the laptop.

In essence, if both were at 15w, the U series would be slightly faster and slightly more efficient. If both were at 45w or above, the HS series would be slightly faster and slightly less efficient. However, they aren’t at the same wattage. The FW16 can supply more power longer term which is why it uses the higher power but faster chips.

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I think it is going to come down to how much wattage the FW13 can drive vs the amount the FW16 can drive. The FW13 may run a bit slower just because it can’t push the power the FW16 can.

I have a FW13 (i5-11th gen) and it has subpar RPSC3 performance, so:

I just bought the FW16 (a batch 6 7840HS because the difference between the 7940 and 7840 is not worth the $200 to me) for exactly the purpose of replacing my old gaming desktop from 2017. RPCS3 will likely be the most used software on it for me, too.

Edit: The biggest difference for me in why I got the FW16 over upgrading my FW13 is the discrete graphics and the greater screen real estate. If you don’t plan to use discrete graphics or are not ready to shell out $2000+, the FW13 7840u will likely do fine with RPCS3, and the comparison between performance I think is likely to be within 15% of a FW16 without the discrete graphics.

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Look up ETA Prime on YouTube. He reviews all types of mobile processors and APUs. He also always includes emulation in his benchmarking. I know that he has reviewed both of the CPUs you’re interested in including the 780M iGPU.

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