PowerLogix 1.1GHz upgrade only running at 650MHz

[Emehr]

The machine:

B&W G3 (Rev B)

The upgrade:

PowerLogix G3 1.1GHz

The software:

Mac OS 9.2.2

CPU Director 1.5f6 (application)

CPU Director INIT 2.0b1 (extension)

The problem:

Metronome and Apple System Profiler report 650MHz as the CPU speed.

The gruesome details:

I'm using an older version of the CPU Director application because the newer one (v2.3b4) doesn't run in OS 9. I've set the speed to 1100MHz and the best I can get is 650MHz.

I'm not sure if it matters but my jumper settings are back to the original configuration for the CPU that was in my Mac before I upgraded (350MHz). (Do the jumpers affect the upgrade at all?)

I don't really understand all of the settings in CPU Director (the documentation is lacking) but this is what I have it set at:

"L2" tab settings

Cache status: On

Boot setting: Enable Cache (other options are 'Disable Cache' and 'Use Firmware Setting')

"PLL" tab settings

New setting: 1100MHz [11:1]

Restart setting: Set PLL on Restart (checked and set to 1100MHz [11:1])

"Options" tab settings

Speculative Access: On

Disable Speculative Access on Restart: (unchecked)

Dynamic Power Management status: On

Enable Dynamic Power Management on Restart: (checked)

For the longest time I just assumed Apple System Profiler was wrong but when Metronome returned the same results I got worried. I get the same results when I boot into OS X (although I think the system reports a speed of 500MHz, IIRC). If anybody has any ideas on how I can get the most out of my upgrade I would appreciate it. Thanks!

 

[Mars478]

The Jumpers are most likely the problem. Switch 'em to a higher config (450) and see what happens.

 

[Emehr]

No dice. I moved the number one jumper to the number four position as shown here to no effect. Apple System Profiler and Metronome still report 650 MHz. TattleTech, interestingly, reports 500MHz (and did so before I switched the jumper as well). Hmm....

 

[Quadraman]

You can try contacting support at Powerlogix or OWC.

 

[trag]

Hmm, for some reason I'm getting no quote button at the bottom of messages.

Anyway, if you're getting 650 MHz when set to a 11:1 ration, then the bus speed of your B&W must be set to 650/11 = 59.1 MHz.

Clearly, the software (CPU Director) expects the bus speed to be 100 MHz, which would give you 100 MHz X 11 = 1100 MHz.

You could try setting CPU Director to a higher multiplier. I'm not sure what the choices are, although, IIRC 20:1 is the highest. 20:1 should give you 1182 MHz, which might be a bit too fast. If there's an 18:1 or 19:1 setting try those.

Alternatively, go over to xlr8yourmac.com and read the articles on setting the jumpers in the B&W then reset yours so that you can actually get a 100 MHz bus speed. Bus speed is the only jumper setting on the B&W motherboard you care about with that upgrade. The cache ratio and CPU speed multiplier settings are ignored by the PPC750GX upgrade.

Wasn't it the case that some B&Ws would do 100 MHz and some would only do slower bus speeds, or am I misremembering. That is, they all had the settings for all teh speeds, but on some the hardware (chips) weren't chosen for the 100 MHz bus speed?

 

[waynestewart]

I have a PowerLogix 1.1 ghz processor that's in a B&W G3. It ignored the motherboard jumper settings as far as processor speed went. I never did try changing the bus speed though. Last time I fiddled with it was a couple of years back but I believe the default speed was 650mhz. I had a problem finding a version of CPU director that would work with the two OSes on it.

When CPU director wasn't functioning it went to the default speed. By non-functioning, I mean I was able to change settings but they actually did nothing.

I also had a problem with an extension conflict in OS9. Try using extension manager to turn off all unnecessary extensions and see what happens.

For OSX make sure that version is compatible with that exact version of OSX. It seemed that every time they updated 10.4, I had to download a new version of CPU director.

My B&W is currently in storage across town but I could likely pick it up next week

 

[Emehr]

Okay I emailed OWC's tech support. In the meantime...

Metronome indicates that my bus speed is indeed set to 100MHz. I double checked my jumpers and they are correct for that setting (jumpers 5,6,8, and 9 set). TattleTech, on the other hand, says the bus speed is 76.73MHz (with the CPU speed at ~500MHz). Not sure which to believe.

I tried slower CPU settings (such as 350MHz and 400MHz) in both OS X and OS 9 and the system still reports 650MHz (OS 9) and 500MHz (OS X). It's like CPU Director has no effect on the CPU. I'm sure the INIT is loading at startup because the splash screen shows up.

@waynestewart: did you ever get yours to run at full capacity? I'm starting to wonder if it actually is an extension conflict because CPU Director is essentially useless. But it's also useless when I boot into Tiger (10.4.9, the last version that CPU Director apparently works with) so I don't know what to think there.

Thanks for the responses so far!

 

[H3NRY]

If you enable dynamic power management, doesn't that mean the CPU drops to half-speed when possible, as in idling while you look at a CPU speed screen? CPUD and other speed sensing utilities are somewhat suspect because you don't know what they are using for a reference or how they are measuring speed.

 

[waynestewart]

Yes, after a little trial and error, I had mine at full speed for both OS 9 and OSX.

If OWC doesn't solve the problem, I'll get my machine out of storage later this week and check the setup on it. Maybe I'll do that anyways. I've been planning on pushing an AIO to the MAX. I've collected most of the parts for that project so maybe it's a good time to make a start.

 

[Emehr]

I received a reply from Otherworld Computing (on a Saturday, no less!). I'm posting it in its entirety for future reference...

PowerPC 750FX and 750GX upgrades support a feature called "dual-PLLs". These processors have two software-configurable PLLs that control the speed at which the processor runs. This feature also works in conjunction with the Energy Saver control panel.
One PLL is configured as a slow speed to be used when the processor is idle. The other PLL is configured as the fast speed to be used when the processor is busy. This feature allows the processor speed to be automatically turned down when the processor is idle in order to save power and reduce energy consumption.

This results in a cooler-running processor, particularly important on notebook computers. In order to use this feature, you set the fast processor speed using CPU Director under the PLL tab (the slow speed is automatically set to be 500 MHz) to the speed at which your upgrade is rated. Then, you can select which speed the computer runs at by using the Energy Saver preferences panel. "Highest" corresponds to the setting selected in CPU Director, "Reduced" corresponds to the automatically-configured 500 MHz setting and "Automatic" will result in the slow setting being used when the computer is idle and the fast setting being used the rest of the time.

In short, due to it's dynamically changing CPU speed, be sure the CPU is running an application(s) that taxes the processor while you verify its speed. A quick way to do this is to use the Mac's Chess application. Set it to play itself on its strongest setting, and you should see the CPU jump up to its rated speed.

The response is Mac OS X-centric since Mac OS 9's Energy Saver control panel doesn't have a CPU usage slider but it was helpful nonetheless. So I guess the CPU bumps its speed on an as-needed basis. Interesting.