An original iMac CPU module is modified to use a replacement CPU and cache:

• IBM 466MHz Copper G3 CPU (revision 3.0)
• 1MB of Sync. Pipeline Burst SRAM L2 Cache running 233MHz
  (PB G3/250 and 292MHz reworked modules retain their original cache - see notes below on cache speeds)

(The following info is repeated from the front page)

Note About CPU/Cache Speeds: As listed at Newer Tech's product page, there are two speeds of this MAXpowr CPU upgrade. For 83MHz bus speed PowerBook Wallstreet models (250 and 292MHz), your reworked module will run at at a CPU speed of 458MHz with a cache speed of 158MHz (this is due to the fact these modules use ball grid cache which is not available in faster speeds I'm told). The 66MHz bus speed PowerBooks (233, 266, 300, 333 and 400MHz models) will run at a CPU speed of 466MHz with a cache speed of 233MHz.

The module reviewed here was a 466MHz with 233MHz cache speed model that Newer sent as a review loaner (I did not send my G3/250 module in for upgrading). The real world applications performance difference from the 458/152MHz model (had my original module been upgraded) would probably be very close to the 466MHz model since cache speed is far from a major factor in applications performance. (I'd guess less than 5% difference overall.) However MacBench 5 CPU scores are highly influenced by cache speed, so scores would be significantly lower in that benchmark.

It's actually a plus that the review sample (loaner) module was a 466/233 model since that's what most owners will receive. (The number of PB G3/250 or 292 models are far fewer than the total number of 233-400Mhz models, which have easily replaceable cache chips and therefore would be getting a 466/233 upgrade.)

To better clarify the issue of CPU/cache speeds (due to the cache types of the original CPU module), here's a clip from the Newer Tech product page:

Depending upon which PowerBook you have, the 466MHz processor will run at one of two speeds. This table displays what the final speed of the processor will be after the upgrade is complete.

PowerBook 233MHz w/512k cache will run at - CPU 466MHz, Cache 233MHz

PowerBook 250MHz w/1MB cache will run at - CPU 458MHz, Cache 152MHz

PowerBook 266MHz w/1MB cache will run at - CPU 466MHz, Cache 233MHz

PowerBook 292MHz w/1MB cache will run at - CPU 458MHz, Cache 152MHz

PowerBook 300MHz w/1MB cache will run at - CPU 466MHz, Cache 233MHz

PowerBook 333MHz w/512k cache will run at - CPU 466MHz, Cache 233MHz

PowerBook 400MHz w/1MB cache will run at - CPU 466MHz, Cache 233MHz

Owners of the original PB G3/233 without backside cache cannot have the module upgraded (there's no circuit connections for Newer to add backside cache chips on that module - those owners should wait for the Powerlogix PB 'BlueChip' Upgrade to start shipping. A reader noted Outpost informed him that the ship date is expected to be Oct 15th, 2000, but I've written to PL for a firmer date).

Compatibility: (repeated from the front page)

The MAXpowr PowerBook CPU Upgrade is compatible with the following models:

• Apple PowerBook G3 1998/1999 models - (233Mhz w/512K cache {cacheless 233Mhz modules cannot be upgraded}, 250MHz, 266MHz, 292MHz, 333MHz and 400MHz models)

  It's not compatible with the first PowerBook G3 (aka Kanga, often called the 3500 since it used a PB 3400 style case and display)

OS Version Compatibility:

Although I suspect any OS that shipped with your Powerbook would work fine, Newer's product page lists OS 9 and higher.

Test System Hardware Summary

• Apple PowerBook G3 1998 (G3/250)
• 512MB RAM (two 256MB low-profile SODIMMs were loaned for this review from Transintl.com)
• IBM Travelstar 20GB (20GB) IDE hard drive (appx 30% full)
  (This is the drive shown in my Wallstreet Hard Drive Upgrade article)
• Original DVD-ROM drive
• ATI RageLT onboard video (4MB SDRAM)
• OS 9.04 w/all updates applied, VM off, QT 4.1 [No Libmoto]