Wasn't Sega also mooting a cart version of the Saturn at one point to bring down build costs? That would have probably worked okay with the "low ram" configurations you mention.
512KB SDRAM and 256KB sound ram would have seemed okay if you were sat in 1992/1993 thinking about a single CPU, 2D focused cart based machine.
I believe there are some old rumors pointing to that in the early days...I believe there's a Sega fan archive site that has sources of the engineering team but I'm not sure right now...
Hopefully that wasn't something mixed up with 32X development which actually came later after Saturn was well into development.
It's also possible that they were indeed planning for a cartridge and CD-ROM combo console which would eventually rely on CD-ROM...however the Saturn's arcade hardware (Sega ST-V) board runs on cartridges.
SH2's were developed that ran at up to 40 mHz, but whether that was on the same process and/or passively cooled I have no idea. If Sega had been able to slap in a 40 mHz SH2 at the cost of a heatsink and fan I do wonder if it might have been worth it ...
I think some later codecs were developed that ran on the two CPUs, as Saturn video did improve markedly over early games. Couldn't swear to it though, one's memory gets confused with what the DC was doing on its SH4 (320 x 240 mpeg took 50% CPU time iirc, could run in parallel with all normal game operation e.g. Space Channel 5).
There are many variations on SH2 CPUs...the 32X also used dual SH2s.
It's worth noting that barely a few years after the Dreamcast based NaOmi Arcade hardware board came out, that Sega made the Dual SH4 CPU and Sega Custom 3d chip powered Sega Hikaru Arcade board (Brave Firefighters, Virtual On Force)
NaOmi 2 was also based on DUAL SH4 CPUs, but also dual graphics (PowerVR) plus a special T&L chip "Elan" (Virtua Fighter 4 and revisions)
Sega's internal hardware engineering staff had some goals, rather ambitious.
As for the video codecs in Sega Saturn did actually greatly improve later on.
The U.S. localized Fighters Megamix and Last Bronx...Burning Rangers, Panzer Dragoon Saga and Shining Force III did have improved video quality.
The VCD as far as games was mainly a benefit for Japan only games like a few that used Anime art style cut scenes and a few that used live action cut scenes where the video was main attraction.
What's 'great' about it? A convoluted mish-mash that's not particular good at anything, Saturn smacks of a botched engineering job rather than a great console. Bad for devs, bad for the product, bad for Sega's finances. It's certainly interesting and a great case-study, and well loved by fans because of the games, but the machine itself is something of a joke AFAICS - how not to design and build a console.
That's a bit short sighted to say.
As far as the development of Saturn, you have to look at the previous Sega Arcade hardware and games around back then.
Rad Mobile and G-Loc definitely didn't use polygons and these games had far more advanced graphics than Out Run and After Burner series up to that point.
Rad Mobile did get a reprogrammed conversion (Gale Racer which wasn't released outside Japan and was an early launch era game) which implemented the use of polygon cars and tracks instead of how the arcade hardware used sprites.
Sega's finances were much more greatly affected by the "botched" North American launch and lack of maintaining public relations with devs afterwards as well as hiring a guy who was blocking a lot of Japanese games from being localized.
Core Design developed Tomb Raider on Saturn with features not available on PlayStation like water effects... Sega apparently never tried setting up some deals with Core Design so when Eidos got them they published multi platform.
The lack of sticking to Saturn for the long term and specially the reaction to the Nintendo 64 U.S. sold out launch holiday season in 1996 may have made Sega more thirsty to copy and paste at the cost of a console launch and bad public relations.
You're right, my fault: the Saturn had 2 x 4Mbit SDRAM chips in parallel over a 32 bit bus; it was the 32x which had one single 2Mbit (that's right, it's not a typo) SDRAM chip over a 16 bit bus.
I guess Sega took a lot of inspiration from the arcade machines, where it was pretty common at the time to have multiple CPUs (also with different architectures) and dedicated ASICS.
I often wondered if the end result (the Saturn) could have been better or less expensive (or maybe a bit of both) if Sega had followed the Nintendo route with only two powerful and complex custom chips instead of a multitude of small custom, semicustom and off-the-shelves chips. Certainly Sega was aware of what Nintendo was doing as Silicon Graphics first had approached Sega of America to pitch their low cost, entertainment 3D solution.
The major problem in thinking about this is that back then Sega had targeted a 1994 thereabouts launch to build an install base ahead of Nintendo before Sony announced their plans.
It seems like an interesting what if scenario however Virtua Fighter 1 granted huge sales for an initially successful Japanese Saturn launch, capitalized by Virtua Fighter Remix (which actually was a ST-V arcade title) and Virtua Fighter II in 1995.
If Sega Saturn was to be pre-planned for 1996 console launch then we would have to consider the 66Mhz Dual SH3 set up with some evolution of Sega's own plus custom secret Nvidia Nv2 chipset which being quads based is far more interesting to have seen.
However the difference if choosing SGi would be some dramatically different solution than the N64.
I think one of the biggest technical feats on the Saturn was Virtual Fighter 2 running at 704x480 @ 60 by effectively using the VDP1/2. It used the saturn's high resolution mode for both background and polygons and at the time it really stood out compared to 3D fighters on the Playstation.
Who knows what tricks would have been found to maximize the pants-on-head hardware if the system would have survived longer but I think games like Burning Rangers show could have been possible (at better frame rates hopefully).
Its always nice to have these tech threads for older hardware since there weren't many (if any) online communities available to discuss them when they were relevant.
Sega's AM3 developed Last Bronx and the Japan only Dead or Alive Saturn conversion of the Arcade versions (from Model 2) did surpass Virtua Fighter II in technical terms.
I believe there were other Japan only fighting games that targeted the similar modes.
At some point around 1997 when it was after Sega's new Graphics Libraries developed by Sega-AM2 were released, there was an army of games being released and developed both as 3d and 2d games in Japan...sadly many of those games were not localized.
The botched public relations handling in North America caused more problems and that's leading into 1998 where more Japanese Saturn games were cranking out...leaving Sega to skip a holiday season which ironically enough they actually had skipped before by not having enough Genesis games during Saturn launch.
There's not enough VRAM to store 704x480 and an NTSC TV couldn't display that w/o interlacing anyway so it's really 704x240, maybe with interlacing (so more like 30 Hz?)
Using that high resolution mode meant 8-bit rendering, which meant a much more flat, static, less vibrant look with no lighting. The VDP2 layer helped a lot though.
There were PS1 fighters that used 512x240 or so with actual lighting. Soul Blade was 640 wide IIRC.
Fighting Vipers, and Fighters Megamix were Sega-AM2 reprogrammed conversions and original title for Saturn. Both fighting games use a lower resolution but they actually featured lighting effects.
Iirc Fighting Vipers was a 1996 release with Fighters Megamix a 1997 release.
One of the craziest things I learned about that generation, and it made me thing "Oh my god what if....". If you think about the shortcomings of Saturn because of it's exotic hardware configuration, and the restrictions placed on N64 hardware by Nintendo, not just the insistence of using carts, but requiring developers to use specific features that crippled performance, it makes you wonder what a Sega console with N64 hardware would have been like. Much faster than what we got with 64 because developers would have been free to tune the games to their preference, and without the space limits of carts. It isn't just that Sega could have had a system that matched N64, I think gamers might have even got more out of it in the long run.
I feel that Saturn, like Nintendo 64 didn't really realize their full software potential mainly due to Sega rushing into Dreamcast and causing a console gen jump which the competition cannot just leave an advantage of over a year...
Nintendo 64 had a lot of potential with the 4MB ram pack and larger 512Mb games (64MB) plus potentially matured dev tools and U.S. install base could have helped the RPG drought N64 didn't need.
A possible Super Mario 64 2 on 4MB ram pack required plus 64MB cartridge plus a Pilotwings sequel, Mario Kart sequel etc would have set some new watermarks.
Likewise for Saturn plus 4MB ram Cartridge and matured development tools which as far as the cartridge despite only one 3d game using it...it wasn't enough.