Apple Power Mac CPU upgrade card cache question on Quadra 700

[9646gt]

I just received a Quadra 700 that was upgraded with 68mb of RAM, 1GB HDD, and has an Apple branded Power Mac 601 upgrade card in it. I can turn the card off in the Apple control panel for it, but I am curious about something. Does anyone know if the built in cache will continue to work with the 68040 when the processor is disabled? I can't find any cache upgrades anywhere for the Q700 and would like to use the card in this way. 

I'm debating just selling the card to someone who needs it in their collection because I'm just not sure it will be enough to make any substantial difference in being able to play early PPC games and would probably be better off using my iBook G3 500mhz or my MDD 867DP

 

[Fizzbinn]

I'm fairly certain the L2 cache on the PowerPC upgrade is exclusively/only used when running in PowerPC mode. When you run in 68040 mode the entire card is basically ignored. 

 

[jessenator]

Were there any other 040 L2 upgrades besides the MicroMac Quadra Cache?

If you go to MicroMac's website (which is still up and not updated since like 1997, just like the Space Jam movie website), there is a phone number you can call, which connects you to an individual in charge of the remainder of MicroMac's inventory. Last time I called there were no more accelerators, but I didn't even bother ask about the L2 cache items. No harm in calling I suppose, though you'd have to pay sticker price for them.

Just don't use the online order form  

 

[9646gt]

I'm fairly certain the L2 cache on the PowerPC upgrade is exclusively/only used when running in PowerPC mode. When you run in 68040 mode the entire card is basically ignored. 

I'm thinking that may be the case but didn't know if someone around may have knowledge otherwise. 

 

[9646gt]

Were there any other 040 L2 upgrades besides the MicroMac Quadra Cache?

If you go to MicroMac's website (which is still up and not updated since like 1997, just like the Space Jam movie website), there is a phone number you can call, which connects you to an individual in charge of the remainder of MicroMac's inventory. Last time I called there were no more accelerators, but I didn't even bother ask about the L2 cache items. No harm in calling I suppose, though you'd have to pay sticker price for them.

Just don't use the online order form  

I was just looking at their Cache cards and careless mods today. I may have to call them!

Edit: called and got the voicemail of a guy with a strange (to me lol) accent. Didn't leave a message. Did you call the area code 949 number at the bottom of the page?

 

[jessenator]

They should direct to the same line. And yes, the guy I spoke to had a German accent  

 

[Fizzbinn]

Were there any other 040 L2 upgrades besides the MicroMac Quadra Cache?

Looks like DayStar Digital had the "FastCache Quadra" 040 L2 cache card upgrade:

https://archive.org/details/DayStarCatalogJuly1994/page/n5/mode/2up

 

[jessenator]

that's probably what the Quadra Cache looks like, too  

I love how generic that GIF is

 

[jeremywork]

Unfortunately the 50/66MHz PPC and the similar 100MHz one only allow the cache to function in PPC mode.

The 'FastCache Quadra' uses the PDS slot, and works with the QuadControl control panel, resulting in significantly better built-in-video performance, as well as raw CPU speed. There are also cache modules that sit between the 040 and logic board, preserving the PDS slot. Some also multiply the bus clock to provide a 50MHz 040 on top of the cache. I haven't been so lucky to find one of those yet.

Daystar's rarer 80Mhz 601 with RAM expansion will allow the Cache to function in 68k mode (with Daystar QuadControl control panel- still says 128k in 040 mode despite being 1M in 601 mode) as well as the 72-pin RAM too.

 

[9646gt]

Unfortunately the 50/66MHz PPC and the similar 100MHz one only allow the cache to function in PPC mode.

The 'FastCache Quadra' uses the PDS slot, and works with the QuadControl control panel, resulting in significantly better built-in-video performance, as well as raw CPU speed. There are also cache modules that sit between the 040 and logic board, preserving the PDS slot. Some also multiply the bus clock to provide a 50MHz 040 on top of the cache. I haven't been so lucky to find one of those yet.

Daystar's rarer 80Mhz 601 with RAM expansion will allow the Cache to function in 68k mode (with Daystar QuadControl control panel- still says 128k in 040 mode despite being 1M in 601 mode) as well as the 72-pin RAM too.

Thank you, I wish I could just find a cache upgrade and just get rid of the PCC card. Maybe I can find someone that has something at a reasonable price that I can sell my PPC card and pick it up  

 

[Franklinstein]

Unfortunately the 50/66MHz PPC and the similar 100MHz one only allow the cache to function in PPC mode.

The 'FastCache Quadra' uses the PDS slot, and works with the QuadControl control panel, resulting in significantly better built-in-video performance, as well as raw CPU speed. There are also cache modules that sit between the 040 and logic board, preserving the PDS slot. Some also multiply the bus clock to provide a 50MHz 040 on top of the cache. I haven't been so lucky to find one of those yet.

Daystar's rarer 80Mhz 601 with RAM expansion will allow the Cache to function in 68k mode (with Daystar QuadControl control panel- still says 128k in 040 mode despite being 1M in 601 mode) as well as the 72-pin RAM too.

The Daystar PowerPro cards are super expensive (I've only seen them over $1000). I wouldn't throw it out of someone gifted me one, but it's not worth buying when I could just get a 7100/80 (or something even faster) to run my PPC apps for way less. More like one of those gee-whiz nerd status symbols than anything, like the Radius Rocket or Micron XCeed Color.

'040 PDS cache cards generally only function with an associated control panel so sometimes people may reinstall the OS without the drivers and never know it's there. Also they're sometimes not well-labeled if someone just finds one sitting in a pile. I'm not sure what the '040 socket caches require but I'd assume they also need a control panel of some sort. Again if someone pulls the hard drive or reinstalls the OS without drivers a layperson may never know if there's a cache card installed.

Aside from the possibility of the overpriced Daystar card, none of the regular PPC Upgrade Cards will allow you to use the card's caches in '040 mode; it's one or the other with a custom ARM-based microcontroller on the PPC card managing the transition and the 601-to-'040 bus translation. 

 

[jeremywork]

Daystar's rarer 80Mhz 601 with RAM expansion will allow the Cache to function in 68k mode (with Daystar QuadControl control panel- still says 128k in 040 mode despite being 1M in 601 mode) as well as the 72-pin RAM too.

Upon more in-depth testing, I discovered this statement needs significant revision. 

TL;DR is the 72-pin RAM and 1M cache are exceptionally fast in PPC mode (competitive with x100 series) but the cache does not seem to have a measurable effect in 040 mode, and furthermore the 72-pin RAM is significantly slower than the 30-pin RAM when in 040 mode.

Rather than checking performance difference in CPU benchmarks, I ran ATTO's performance utility on a RAM disk to see more granularly the effectiveness of the memory system. These results were corroborated by CPU benchmarks for accuracy, but those tests aren't shown here.

The ATTO test will show markedly improved performance whenever the write can be absorbed by the cache entirely, and as the size of the writes surpasses the cache size the speed will begin falling back toward the speed of the un-cached memory. With no cache enabled the line will tend to be relatively flat. 

Warning: information overload inside - all tests performed on Q950s

https://imgur.com/a/AfHidJ5

I did my best to assemble these in a sensible order. Reading the captions in order may help.

P.S. While testing I discovered a bug/irregularity in Daystar's QuadControl panel. Verified on two different systems; if you uncheck FastCache Quadra 128k and don't restart the cache is still verifiably enabled. If you uncheck do restart, the panel prevents the card from being detected by the system from there out. The only way to re-enable the cache is to delete the QuadControl Preference file from System Folder/Preferences and restart again. Hope this helps someone, I thought for a minute I killed the cache card!

 

[register]

As far as I remember any 040 cache memory cards were of limited use because of lacking software compatibility. As mentioned before, a special control panel is used to enable or disable the cache usage, mainly to allow enabling it for compatible software and disabling to avoid crashes while using incompatible software. Some contemporary reviews were not convincing and thus I never considered to try a 040 cache card.