General question regarding EE/IOP and VU settings

[jlwmanagement]

Hi All,

This is not game specific but I am wondering something. I see some "set clamping to full" advice floating around there and it got me thinking. Are the recommended settings for VU and EE set as such to balance performance with accuracy?

More specifically, my system is pretty powerful, so would I get more accurate results (accuracy is my main concern) by setting:
EE/FPU Advanced Recompiler Round Mode to Chop, or is there a more accurate setting like Nearest? Also regarding EE, would Clamping set to Full be more accurate than Normal?

For VU, would VU0/VU1 Rounding of Nearest be more accurate than Chop? Also would Clamping for VU be more accurate for Full or Normal?

I apologize if this question is elementary. I want to get the most out of my gaming experience

Thanks in advance!

[miseru99]

It's not really about higher or lesser compatibility some things just can't be made same way on pc as they are on ps2 and those modes are different ways of dealing with it. Those options are changed by "automatic game fixes" when needed to begin with soo yeah leave all of those options on default unless having problems that could be caused/fixed by rounding ~ like FFX inverted chars at boss battles or clamping ~ for example messed graphics in MR3 which are not set automatically by some reasons - like ultra care for FFX frames ~ps2/pcsx2 flag game lol@_@, MR3 working fine and faster with SuperVU or simply game being rare and nobody bothered with it yet.

So yeah recommended settings for those - default ones. You'll do more bad than good by just setting them to different ones and forget.

[billyash]

May be you are wondering the difference all roundin mode (nearest,negative,etc) and clamping (none,extra,etc)?
Actully im so curious technically bout them?

[nosisab Ken Keleh]

Hi All,

This is not game specific but I am wondering something. I see some "set clamping to full" advice floating around there and it got me thinking. Are the recommended settings for VU and EE set as such to balance performance with accuracy?

More specifically, my system is pretty powerful, so would I get more accurate results (accuracy is my main concern) by setting:
EE/FPU Advanced Recompiler Round Mode to Chop, or is there a more accurate setting like Nearest? Also regarding EE, would Clamping set to Full be more accurate than Normal?

For VU, would VU0/VU1 Rounding of Nearest be more accurate than Chop? Also would Clamping for VU be more accurate for Full or Normal?

I apologize if this question is elementary. I want to get the most out of my gaming experience

Thanks in advance!

Since you stated your system is powerful, for the speedhacks the best is having none or at least the minimal possible.

About the clamping and rounding methods, the answer is a bit more complicated and too long to explain totally in a post reply. You can find more information searching for "denormal numbers" and some other terms following the brief explanation.

To understand those settings you must understand how float point calculation was standardized in IEEE 754 and some actual implementations by Operational Systems and the CPUs themselves.

Still, PS2 seems to use non standard methods to deal with that problem, which may pose problems for the CPU internal algorithms to deal with them. On the other hand, the cases where denormals become an issue aren't frequent, so in principle you should keep the defaults for they are faster and compliant with the standards.

Yet, since the PS2 method is not totally comprehended to date, some games may force wrong results when denormals happen, the big problem is there is no better set in this case, where it happens in a brief situation in certain game, you must attempt one the methods which brings the best result or in severe cases, to even allow the game to continue (edit: even in this case you should consider returning to defaults once the situation is passed).

In less words, those are software algorithms to deal with the situations where denormals can't be resolved by the CPU and could return a exception condition, so, use the defaults for they are faster. If experimenting glitches or crashes, so try the alternatives, that is the better cost/benefit and there is no warranty a problem would not arise exactly for using aggressive and probably excessive rounding or clamping.

[jlwmanagement]

Thanks nosisab Ken Keleh. I appreciate your detailed reply. I will leave the standards