ok, test updated;
GBA - PSP wins easily. gpsp on PSP can play games like gba. GBA is originally a bit widescreen so you have 3 screen modes to suit your tastes. Scaling isn't noticeable mainly because PSP uses bilinear filter that applies to every frame of rendered output. Bilinear filtering doesn't slow down at all in PSP emu's - it's one of pro's of PSP GPU. GBA games play flawlessly on PSP, most of them 60fps without fs, but in Mario Kart i've noticed that there are definitely some frameskips. But emulation is soo good that after a few minutes i've forgotten that i'm playin' PSP emu instead of real GBA. Sound is also excellent. I've tried about hundred roms, with only one being not played properly - SuperMario Advance3 - Yoshi Stories.
gpsp port on gp2x isn't any real competition - yeah i'know that persons working on it have a break now - but we are talking about
current GP2X vs. PSP emulation status.
NEO-GEO - that is a bit tricky. gngeo with rage2x VS. NJ's emu;
1.You have to convert most roms in converter to generate cache. gp2x has 64mb ram so the cache files can be smaller, those on psp are way bigger so they take more space on memory card. plus for gp2x.
2.Albeit psp has only 32+4mb ram it loads roms like a blitz, approx 4 times faster than gngeo. And when you play for example LastBlade2 - on gp2x i've had a major lag on beggining of each stage battle, it lasts few seconds and fps went low to 5-11 fps and goed back to 55-60. I'm certain that lag was there because some gfx rom data had to be transfered to memory from cache file. On PSP there aren't any lags-strange because as we know it has only 32+4mb ram. big plus for PSP.
3.Speed. on mine gp2x i've achieved to OC gngeo to 260mhz. I could play MS with 11.025 sound and
auto frameskip, it was mainly 0 fs. But games with 22.050 sound were too slow and unplayable.
on PSP, NJ emu is clocked default to 333mhz and plays most games with 0 fs and 60fps
WITH 22050 sound default. Frameskip off. As someone mentioned before - in MS are slowdowns - on gngeo, on psp, on pc, on arcade machine. this game was pushing hardware to its limits and real neogeo could barely handle it
But - other roms - gameplay on psp is fluid, really. It's better than on gngeo and with better (22.050 sound) And
not everyone's gp2x will OC to 260mhz or even bigger and every PSP can run at 333mhz. (with auto frameskip and 11.0125 sound PSP could go down to 266mhz). Pro's for PSP
4.Screen.
neogeo - 304x224
gp2x- 320x240
psp-480x272
neogeo suits gp2x screen well, almost perfectl. nothing could be added.
psp - well - you can play original (small screen), 3:2 that maintains aspect ratio, 14:9, and 16:9. There is free bilinear filter added so resizing do not looks bad. Instead, it really looks nice - a neo geo game on psp screen. I've played MS2 resized to 16:9 and was amazed how beautiful this game looks, really.
I prefer to play neo geo on psp now, with full 16:9 resizing. Gameplay IS better, more fluent, better sound.Colors imho are more vivid on psp (it has 16.7m screen, gp2x has 262k). This is my subjective opinion and PSP wins
5. TV output. We'are talking about portable gaming but we couldnt forgot that you can play games on TV with gp2x. plus goes for gp2x.
6. Wifi ad-hoc support. plus goes for psp
PSP-4 (no-lags, faster, screen, wifi )
GP2X-2(3) (smaller cache files, tv output (screen) )
NJ's emu for PSP wins
(yeah, you can add one point for gp2x because of screen - but neogeo on psp is faster, no-lagging, it is simply better)
Ahh - PSP screen trails - To be honest - I haven't spotted them. On NJ's emu (MVS,CPS1,CPS2) they are unnoticeable.
Yes, PSP lcd has its trails - as I mentioned before most noticeable in SNES emu, but there aren't trails in NJ's emu's. And do not forget that PSP screen has a way better viewing angles that gp2x.
And batteries - on gp2x i'm using energizer 2500 mAh. Those AREN't crappy batteries.