techworks non-ram?

[chelseayr]

just wondering as I found techworks' web address and tried three different year samples on archive.org but all it returned was nothing but just ram (beside some networking items) so I'm curious about that this particular its-a-cache-not-a-ram-stick visible in the closeup photo of the cache slot itself?

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(and no even if I reposted this into the trading-ebay section I don't want it either way, its not a low-profile configuration)

p.s and yes I know the "bomb-y" battery is long missing thankfully

 

[David Cook]

Based on the ports, the number of RAM slots, and the video card, this looks like a Power Computing PowerWave motherboard. The user guide says the default cache is 256K, upgradeable to 512K or 1MB. So, perhaps the lucky buyer has a larger aftermarket cache. Might even fit into a standard 7500/8500/9500?

The RAM is not optimally installed on this motherboard. As interleaving requires matching DIMMs in bank A<->B.

 

[MOS8_030]

Techworks supplied Power Computing with caches and memory.
One of the "secrets" to Power Computing's faster Macs were bigger caches.
I have a Techworks 1MB cache I bought for my 8500. It made huge difference in performance over the stock 256K.
(I got a discount from Techworks stuff because I worked at Motorola.)
Unfortunately I had to remove it when I installed a carrier card with a 450mHz G4 interposer.

 

[chelseayr]

mos8_030 ah so sorta like an oem deal? that could explain why I was wondering about only finding ram on the sample archive.org pages

thanks still, wonder if some happy buyer would want to put that particular cache module to use

 

[David Cook]

wonder if some happy buyer would want to put that particular cache module to use

I'll post close-up photos and test results after it arrives.

 

[chelseayr]

you? heh well doesn't surprise me someone on this forum went after it. anyhow when you do get it I could be curious as to the actual spec for it just for curiousity sake

 

[David Cook]

anyhow when you do get it I could be curious as to the actual spec

Yes. I'll test it and answer any questions that I can.

Part of the reason for the purchase was to get the motherboard, as it seems to accept a standard ATX power supply. I'm hoping it will fit in a standard PC case. Basically, I'll try to make into a working computer again.

 

[David Cook]

I received the items today. That's pretty fast shipping from Greece to Chicago. For $94 (including shipping), I received:
* CPU (initially worked and then didn't in Power Mac 7300) Maybe need a recap or new solder paste. May only work on Power Computing board or 7500 series?
* Power Computing motherboard. I have ordered an ATX power supply to test it.
* Works: 96 MB of RAM (32 x 1, 16 x 3, 8 x 2). Two of the 16 MB sticks needed cleaning with an eraser and IPA in order to work.
* Works: XClaim Twin Turbo GA video card with VGA & Mac output and 4 MB memory. Supports 640x480 up to 1600x1200.
* Works: 512 KB cache card. Compatible with 7300 series as well.
Since the seller had not tested these items, I was very fortunate.

As promised, here is the back and front of the Power Computing 50042 Techworks cache card:


Separately, I purchased an Interware Booster R-200849 W103-B PM97-016 512 KB cache card:


Using a Power Macintosh 7300 200 MHz 604e with the purchased 96 MB RAM, System 8.1, and extensions disabled, I tested the stock 256 KB cache as well as the two 512 KB cache cards:


As you can see, the Power Mac 9600/200 (same CPU as I tested in the 7300/200) with its stock 512 KB cache has the overall same performance as either of the 512 KB cache cards in the 7300/200. However, the stock 256 KB cache card in the 7300/200 computer has a significantly lower performance. At least as far as benchmark testing, doubling the cache size produced a 25% boost.

For the 7300 series, DIMMs are specified at 60 ns, but the L2 cache is specified at 11 ns, and I assume the L1 cache is 5 ns. Therefore, it is understandable why fetching from the cache is so much faster, and allows the processor to run at full speed more often.

 

[MOS8_030]

Here's an image of the Techworks 1mb cache I used in my 8500.

 

[MrFahrenheit]

The ns speeds you mention, when read off the chips, is likely not correct. I’ve seen memory speeds listed as “xxxx-8” and “xxxx-80”. Likely -5 and -11 are 50 and 110ns speeds.

 

[David Cook]

The ns speeds you mention, when read off the chips, is likely not correct. I’ve seen memory speeds listed as “xxxx-8” and “xxxx-80”. Likely -5 and -11 are 50 and 110ns speeds.

Sorry for the confusion. I should have cited my source. The Apple Power Macintosh 7300 Service Source, page 43/44 ("Memory - 5")



The 5 ns number was calculated as 1/200 MHz or 0.000 000 005 as I assume the CPU's internal L1 cache runs at the processor speed.

 

[Fizzbinn]

@David Cook I did some L2 cache tests with my 7300 a while back that mostly match yours. I thought it was interesting to see how more L2 cache also improves disk and built-in graphics speed.

L2 Cache modules tested: None, 256KB, 512KB and 1MB

Spoiler, more L2 cache is generally better, but doesn’t hold a candle to my G3 upgrade card (although it would be neat to see what a lower end G3 233Mhz/512KB scores, guessing it would still be a lot faster).

Power Macintosh 7300/200 MacBench 4.0 test results:

• Mac OS 8.6
• VM off
• Appletalk off
• 64GB SSD on Sonnet 133 PATA PCI
• Sonnet G3 450Mhz/1MB processor upgrade (with no Logic board cache module installed) used for last test

I also created a reference doc on L2 Cache modules on another site in case anyone is interested:

PPC Macintosh L2 Cache Modules

The goal for this resource article is to document identification and reference information on the various L2 cache modules for Power Macintoshes and clones. While at a quick glance many of these L2 cache DIMMs look similar there are different pin...

tinkerdifferent.com

 

[MrFahrenheit]

Sorry for the confusion. I should have cited my source. The Apple Power Macintosh 7300 Service Source, page 43/44 ("Memory - 5")

View attachment 42827

The 5 ns number was calculated as 1/200 MHz or 0.000 000 005 as I assume the CPU's internal L1 cache runs at the processor speed.

Thanks for the reference. I learned something new !

 

[David Cook]

I also created a reference doc on L2 Cache modules on another site:

Wow! I just looked at it. Great reference.