Power Macintosh

Guide to CPU Upgrades for AGP G4 Power Macs

Updated 2008.06.04

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The Power Mac G4 started life as a powerful computer, but some are already five years old and could use a speed boost. Although more memory and a faster hard drive can improve system performance, replacing the old G4 with one or two newer, faster G4 processors is just the ticket for processor-intensive work.

Current CPU upgrades range from 550 MHz to 1.5 GHz, and dual processor models offer speeds to 1.33 GHz.

Upgrades on this page may work in any of the following models. Be sure to check manufacturer specifications for full compatibility details. The following numbers are used in the tables below to noted compatibility. At this time, only Sonnet makes CPU upgrades for the 1.25-1.42 GHz MDD models that have a 167 MHz system bus.

1. G4/350-500 Sawtooth/AGP graphics - 100 MHz bus
2. G4/450-500 dual processor - 100 MHz bus
3. Cube - 100 MHz bus
4. G4/466-533 (digital audio) - 133 MHz bus
5. G4/667-733 (digital audio) - 133 MHz bus
6. G4/733-867 (Quicksilver) - 133 MHz bus
7. G4/800-1 GHz (Quicksilver 2002) - 133 MHz bus
8. G4/867 MHz dual (Mirror Drive Door) - 133 MHz bus
   G4/1 GHz (FireWire 800) - 133 MHz bus
9. G4/1-1.25 GHz GHz dual (Mirror Drive Door) - 167 MHz bus
   G4/1-1.42 GHz (FireWire 800) - 167 MHz bus
   G4/1.25 GHz (June 2003) - 167 MHz bus

The information is as accurate as I can find, but specifications and availability are subject to change; I suggest you check with the manufacturer to verify current models. Prices keep dropping, so these prices may be outdated. (Prices are in $US.) In fact, models are added and discontinued so often, it's impossible to keep track of which models are current.

NOTE: These upgrades are not compatible with the Yikes! G4. See our Guide to G4 ZIF Upgrades for Power Mac G3 and G4 "Yikes!" models.

Discontinued accelerators are listed for historical reasons. On dual processor upgrades, cache size is per processor.

The PowerPC 7451 and 7455 have an internal 256 KB level 2 cache. The 7447 and 7457 have 512 KB. The 7448 has 1 MB. All else being equal, the bigger cache will make upgrades a bit faster.

CPU Speed

L3 Cache

Cache Speed

CPU

Estimated Street Price

Giga Designs, CPUs may be overclocked Compatible with 1, 2, 4, 5, 6, 7 - see site for details
1.2 GHz	2 MB	240 MHz	1.0 GHz 7455	disc.
1.4 GHz	2 MB	233 MHz	1.25 GHz 7455B	$219
1.467 GHz	2 MB	244 MHz	1.25 GHz 7455	disc.
1.5 GHz	2 MB	250 MHz	1.25 GHz 7455	disc.
1.53 GHz	2 MB	unknown	1.53 GHz 7455B	$249
1.6 GHz			1.6 GHz 7447A	disc.
1.8 GHz			1.8 GHz 7447A	disc.
dual 1.2 GHz	2 MB	240 MHz	1.0 GHz 7455	disc.
dual 1.3 GHz	2 MB	222 MHz	1.25 GHz 7457	disc.
dual 1.33 GHz	2 MB	280 MHz	1.25 GHz 7455B	disc.
dual 1.4 GHz	2 MB	280 MHz	1.25 GHz 7457	disc.
dual 1.7 GHz			1.7 GHz 7447A	disc.
dual 1.8 GHz			1.8 GHz 7447A	disc.
For the Cube
1.33-1.5 GHz	2 MB	222-250 MHz	1.33 GHz 7457	disc.
For Mirrored Drive Door
1.33 GHz	2 MB	167 MHz	1.33 GHz 7455B	disc.
1.4 GHz	2 MB	233 MHz	1.25 GHz 7455	disc.

Newer Technology MAXPower G4/7447A, MAXPower G4/7448 Compatible with 1, 2, 4, 5, 6, 7
1.6 GHz	512 KB	1.6 GHz	7447A	$230
1.6 GHz dual	512 KB	1.6 GHz	7447A	$400
1.7 GHz dual	512 MB	1.7 GHz	7447A	$500
1.8 GHz dual	512 KB	1.8 GHz	7447A	$600
1.8 GHz	1 MB	1.8 GHz	7448	$340
2.0 GHz	1 MB	2.0 GHz	7448	$399
1.7 GHz dual	1 MB	1.7 GHz	7448	$599
1.8 GHz	1 MB	1.8 GHz	7448	$699

Other World Computing Mercury Extreme Compatible with 1, 2, 4, 5, 6, 7
867-933 MHz	2 MB	173-233 MHz	7455A	disc.
933 MHz-1.0 GHz	2 MB	233-250 MHz	933 MHz 7455A	disc.
1.0 GHz	2 MB	233-250 MHz	1.0- GHz 7455A	disc.
1.2 GHz	2 MB	240 MHz	1.0 GHz 7455	disc.
1.2 GHz	2 MB	240 MHz	1.2 GHz 7455B	$199
1.25 GHz	2 MB	250 MHz	1.25 GHz 7455A	disc.
1.25-1.33 GHz	2 MB	208-222 MHz	1.25 GHz 7455B	disc.
1.4 GHz	2 MB	233 MHz	1.33 GHz 7455B	disc.
1.467-1.5 GHz	2 MB	245-250 MHz	1.5 GHz 7455B	$260

Operator Headgap Used, sometimes overclocked Apple CPUs Compatible with 1, 2 (single-processor model only)
400 MHz	1 MB	200 MHz	400 MHz 7400	$12.77
500 MHz	1 MB	250 MHz	450/466 MHz 7400	$24.77
550 MHz	1 MB	275 MHz	466 MHz 7400	$49.77
600 MHz	1 MB	600 MHz	533 MHz 7410	$39.77

PowerLogix PowerForce G4 Single CPU Compatible with 1, 2, 3, 4, 5, 6, 7
800 MHz	2 MB	250 MHz		disc.
1.2 GHz	2 MB	200 MHz	1.0 GHz 7455	$179
1.4 GHz	2 MB	250 MHz		disc.
1.6 GHz	2 MB	250 MHz	1.2 GHz 7447A	$439

PowerLogix PowerForce 47/55 Compatible with 1, 2, 4, 5, 6, 7
1 GHz	2 MB	200 MHz	7455	$160
1.6 GHz			7447A	$220
1.2 GHz dual	2 MB	250 MHz	7455	$300
1.6 GHz dual			7447A	$429
1.7 GHz dual			7447A	$449
1.8 GHz dual			7447A	$629

PowerLogix PowerForce G4 Series 100 Compatible with 1, 2, 3; $10 more for Cube fan kit
700 MHz	2 MB	unknown		disc.
800 MHz	2 MB	250 MHz		disc.
1 GHz	2 MB	250 MHz		disc.
1.2 GHz	2 MB	250 MHz		disc.

PowerLogix PowerForce 47/48 for Cube Compatible with 3
1.5 GHz	512 KB					7447	$250
1.7 GHz	1 MB					7448	$370
1.5 GHz dual	512 KB					7447	$450
1.6 GHz dual 7447	512 KB					7447	disc.
1.6 GHz dual 7448	1 MB					7448	$680

PowerLogix PowerForce G4 Series 133 Compatible with 4, 5, 6, 7
733 MHz	2 MB	unknown		disc.
867 MHz	2 MB	250 MHz		disc.
1 GHz	2 MB	250 MHz		disc.
1.6 GHz			7447A	disc.

PowerLogix PowerForce Dual G4 Series 100 Compatible with 1, 2, 3 "Early models of AGP have a bridge chip that is not compatible with dual processors. We recommend the PowerForce G4 Series 100 (single processor) for those machines."
800 MHz	2 MB	250 MHz		disc
900 MHz	2 MB	250 MHz		disc
1 GHz Dual	2 MB	250 MHz	7455	disc.
1.3 GHz Dual	2 MB	unknown	7455	disc.
1.6 GHz Dual			7447A	disc.
1.7 GHz Dual			7447A	disc.
1.8 GHz Dual			7447A	disc.

PowerLogix PowerForce Dual G4 Series 133 Compatible with 4, 5, 6, 7 "The PowerMac G4 Cube has a lower capacity power supply and therefore we conservatively recommend installing at most a Dual 800 MHz."
867 MHz	2 MB	250 MHz		disc.
933 MHz	2 MB	250 MHz		disc.
1 GHz	2 MB	250 MHz		disc.
1.2 GHz	2 MB	250 MHz	7457	disc.
1.33 GHz	2 MB	250 MHz	7457	disc.
1.6 GHz			1.25 GHz 7447A	$429
1.73 GHz			1.42 GHz 7447A	$499
1.8 GHz			1.6 GHz 7447A	$629

Sonnet Encore/ST G4 Compatible with 1, 2, 3, 4, 5, 6, 7
800 MHz	2 MB	400 MHz	7455	disc.
1 GHz	2 MB	500 MHz	7455	$170
1.2 GHz	2 MB	unknown	7455	disc.
1.4 GHz	2 MB	unknown	7457	disc.
1.6 GHz			7457	disc.
1.7 GHz			7457	disc.
1.8 GHz			7457	$270

Sonnet Encore/ST G4 Duet Compatible with 1, 2, 3, 4, 5, 6, 7
500 MHz	1 MB	250 MHz	7455	disc.
1.267-1.3 GHz	2 MB	unknown	7455	disc.
1.6 GHz	2 MB	unknown	7447A	disc.
1.8 GHz	2 MB	unknown	7447A	$500

Sonnet Encore/MDX G4 Duet Compatible with 8, 9, and G4 Xserve
1.6 GHz	512 KB					7447A	$450
1.8 GHz	512 KB					7447A	$600

XLR8 MACh Speed G4 Sawtooth Compatible with dual G4/450 and 500 only.
500 MHz	1 MB	250 MHz	7410	disc.
550 MHz	1 MB	275 MHz	7410	disc.

XLR8 MACh Speed G4 ZIF MPe Compatible with dual G4/450 and 500 only.
350 MHz				disc.
400 MHz				disc.
450 MHz				disc.
500 MHz				disc.
550 MHz				disc.

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