PCem performance on AMD laptop APUs

Support and general discussion.
Post Reply
Pedro_Freitas
Posts: 2
Joined: Mon 25 Apr, 2022 2:16 pm

PCem performance on AMD laptop APUs

Post by Pedro_Freitas »

Hello guys. How are you doing?

First of all, I want to thank all the work that has been done to preserve computers' history and, of course, all the memories they bring back.

So here is my question: I need to buy a new laptop, and the Ryzen 7 5700U perfectly meets all my needs. I already read another topic about it (https://pcem-emulator.co.uk/phpBB3/viewtopic.php?t=3739) but I'm still not sure how well (or how bad) this APU can run PCem.

How PCem performes on AMD laptop APUs?

Its a good choice, or an Intel Core i5 1135g7 (that perfectly meets all my needs too) would be a better option?

Thanks in advance!
User avatar
unreal9010
Posts: 160
Joined: Sat 14 Nov, 2020 8:20 pm

Re: PCem performance on AMD laptop APUs

Post by unreal9010 »

As far as PCem is concerned, Core i5-1135G7 would be a better choice.
Note that none of these two processors has particularly fast ST performance. Expect to run virtual machines up to Pentium MMX 200.
Pedro_Freitas
Posts: 2
Joined: Mon 25 Apr, 2022 2:16 pm

Re: PCem performance on AMD laptop APUs

Post by Pedro_Freitas »

unreal9010 wrote: Mon 25 Apr, 2022 4:03 pm As far as PCem is concerned, Core i5-1135G7 would be a better choice.
Note that none of these two processors has particularly fast ST performance. Expect to run virtual machines up to Pentium MMX 200.
Thanks for the tip! Let me ask another question: in the topic I mentioned, the user has the same processor (ryzen 5700u) and is having performance problems. Could these problems be due to incompatibility? Or is he trying to emulate a system beyond the capacity of the host machine?

If I chose Ryzen, would I lose a lot of performance (compared to PCem) compared to the core i5?

PS.: I've never had an AMD processor since the K6-II, but in this case I would prefer Ryzen because of its higher MT performance.
User avatar
unreal9010
Posts: 160
Joined: Sat 14 Nov, 2020 8:20 pm

Re: PCem performance on AMD laptop APUs

Post by unreal9010 »

I can't tell you exactly how much would you lose if you went with AMD Ryzen instead of Intel.
For example, my CPU (12900KF) has a Passmark ST rating of 4,200. It can run everything at 100% when emulating Pentium II 350. The only slowdowns that occur are related to some newly introduced dynarec regressions and have nothing to do with the host CPU, given that they also occur when emulating P133.
On the other hand, people who own 5600X, a processor with a Passmark ST rating of 3,300, have issues maintaining 100% speed when emulating Pentium II 233.
In a Youtube video below you can see that an owner of 10700KF (ST rating of around 3,000) can emulate Pentium II 266 without issues.
Choose a processor that suits most of your needs.
https://www.youtube.com/watch?v=6FVgTlg8iNA
tk421
Posts: 156
Joined: Sat 18 Jun, 2016 6:57 am

Re: PCem performance on AMD laptop APUs

Post by tk421 »

PCem depends very heavily on the single-threaded performance of your CPU. The number of cores is not really all that useful for a program like PCem. The key would be to have a CPU that has an all-core turbo speed of at least 4 Ghz, and a strong single-thread turbo speed of at least 4.5 Ghz. That way you should be able to get the Pentium MMX CPUs running in PCem at 100% emulation speed. You would also be able to use P2 speeds up to 300 Mhz at or close to 100% speed. You might even find some of your programs running at 100% performance on an emulated Pentium 2 450.

My i7 9750h-powered laptop runs my programs at a good level of performance, but it is just shy of providing reliable top performance at P2 450 Mhz and Celeron 533 Mhz CPU speeds, which is what I will strive for with my next laptop purchase.

PCem performance is also heavily task-dependent, so it is a good idea to see which programs you would run with PCem and which programs you might run instead on VMWare, Virtualbox and other emulation/virtualization solutions. Games like Jedi Outcast and Jedi Academy run great on VMWare, but you would need a powerful CPU, if it exists, to run them with PCem. By contrast games like Jedi Knight and Star Trek Armada are a great choice for PCem at 450 Mhz provided you have a better CPU than mine.

Users on this forum have frequently recommended Intel over AMD. I am not sure if the Ryzen is really good enough for top-level PCem performance. Some users have reported good PCem performance with the Ryzen, but as you can see here that has been for desktop PCs.

The only AMD laptop CPU I have read about online that could possibly reach PCem v17 requirements may be the Ryzen 9 5900hx. I have no idea if anyone here has tried this, but it may be an option.

I am a big fan of PCem's Pentium MMX, Pentium 2, and Voodoo 1,2,3 emulation features, and I think it is a great program.
User avatar
leilei
Posts: 1039
Joined: Fri 25 Apr, 2014 4:47 pm

Re: PCem performance on AMD laptop APUs

Post by leilei »

tk421 wrote: Mon 25 Apr, 2022 6:16 pm Games like Jedi Outcast and Jedi Academy run great on VMWare, but you would need a powerful CPU, if it exists, to run them with PCem.
This is applied in real-life too. A Celeron 600 with a Voodoo3 isn't going to run JK2/JA very good, what with the weighted skinning, large textures and song crossfading.
Also PCem doesn't emulate the cache, so much of the would-be cache-lacking CPUs are emulated possibly more faster than what they are.
Post Reply