04404: tnzs: Significant negative performance spike after intro sequence

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
04404	Misc.	Minor	Always	Jul 3, 2011, 12:25	Jul 19, 2012, 11:33

Tester	Haze	View Status	Public	Platform	MAME (Self-compiled)
Assigned To	Haze	Resolution	Fixed	OS	Windows Vista/7 (64-bit)
Status [?]	Resolved			Driver	taito/tnzs.cpp
Version	0.143	Fixed in Version	0.146u4	Build	Normal
		Fixed in Git Commit		Github Pull Request #

Summary	04404: tnzs: Significant negative performance spike after intro sequence
Description	After coining up and starting a game there is a noticeable speed hit on the black screen after the intro sequence before the actual gameplay (dips to <50% here) Need to check if this is a result of the device conversion of the ST001A/002A video chips, or something else, and if so, why. Such a dramatic drop in performance on a Z80 based game is unexpected. I haven't seen any other ST001 based games affected which makes me wonder. (this is not the same as the expected overall performance drop from perfect interleaving introduced many versions ago)
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version	0.139u2
Affected Sets / Systems	tnzs

Attached Files

No.07627 Tafoid Administrator Jul 3, 2011, 14:35	This decrease is due to the changes in the memory system. There are certain games which have a drop in performance in certain places. The same type of issue is present in 04097, when initial startup is very slow due to a lot of what I understand to be memory map thrashing. Specifically, the changes in r9980 are the cause. While not explicitly an emulation 'bug', it's an issue where it causes concern as it's unexpected. Confirming, adding regression and adding related.
No.07628 Haze Senior Tester Jul 3, 2011, 14:40 edited on: Jul 3, 2011, 14:41	Hmm, tnzs doesn't use any kind of dynamic memory map tho apart from banking (as far as I'm aware anyway) I noticed Sly Spy took quite a hit as a result of the memory map changes, and one of the Golden Axes sets is slower than the others for similar reasons (extensive use of the memory remapping) Likewise startup on ms32.c is slow due to the mirroring, but I'm at a bit of a loss to explain this one (which is why I'd flagged it as possibly video related when going through looking at drivers I'd touched recently)
No.07669 hap Developer Aug 4, 2011, 23:00	The slowness is in machine/tnzs.c tnzs_bankswitch_w. Adding something like: if (oldbank == newbank) {return;} doesn't speed it up (unlike namcos1)
No.07670 Haze Senior Tester Aug 5, 2011, 15:38	Well no, because that's a hack around an underlying issue. Is it only the 'modern' banking systems which are affected, or is this hitting the traditional 'deprecated' (but IMHO still better) bankptr ones?
No.08387 Sune_S Senior Tester Mar 18, 2012, 05:34	What's it doing between levels that's so intensive, moving around lots of graphics data for the next level? tnzs dips all the way down to 20% here.