World-first test of the new Power Macintosh G5 Dual Core!

Starting today you can order a Power Macintosh G5 which will display dual processor bars inside the task manager with still only one processor on the motherboard – how does that work?

It's called Dual Core and it's a part of the new PowerPC 970MP chip from IBM. Dual core is two processor cores placed on the same chip which makes for faster transfer speeds between the processors compared to placing them side-by-side on the motherboard. The processor has 1MB L2 cache per core.

We have tested the new Power Macintosh G5 2.3 Dual Core which only has one processor on the motherboard but theoretically should be faster than the old Dual machines anyways. Apart from the new processor, Apple have also transitioned to DDR2 memory like in the new Powerbook G4. The motherboard has in total eight DIMM-slots which makes for a maximum of 16 Gigabytes RAM. The card slots are now of the PCI Express type, the graphics card has a 16x slot and there is one 8x and two 4x slots available.

The appearance of the computer has not changed very much and few could tell the difference from the old one. On the rear the connections for Airport- and Bluetooth-antennas have disappeared. Instead there is a 10 inch long rubber enclosed antenna running along the rear.

Apple introduced the possibility of "link aggregation" according to the 802.3ad standard in Mac OS X 10.4 Tiger and now there is two gigabit connections available on the rear of the Powermac G5. If you use both in combination you get a maximum theoretical transfer speed of 2 Gigabits per second and more redundancy. The modem port has been removed for good.

One very irritating detail is that Apple have introduced a new standard with the new power-cord – they're using a type that we haven't seen before which is guaranteed to trigger many loud swearings the day you end up losing the cable (who hasn't?). The new cable will surely be available at your nearest Apple Center/Store for 3-5 times the price of the old one. We have to ask ourselves: Why?

The graphics card is a nVidia 6600 and is mounted in a 16x PCI Express slot. The card has 256MB of videomemory and supports dual monitors through two DVI-connections. One of the DVI-connections is of dual-link type and can be used with the giant 30-inch display from Apple.

Just like before a SATA interface is used for storage and aside from the included 250GB 7200rpm harddrive there is room for one additional harddrive. A new optical drive supports Dual-layer DVD's and writes up to 8.5 Gigabytes per disc.

As we open the side door we can clearly see why there still is no Powerbook G5 – the processor heat sink is huge and it's clear that Apple have worked hard on the cooling problem with the new Powermacs.

All new Powermac G5:s ship with the new Mighty Mouse which we have previously reviewed here on 99mac (Swedish only).

Testresults Xbench 1.2

We have compared the new G5 DualCore 2.0GHz and 2.3GHz with a old watercooled G5 dual 2.5GHz. The dual 2.5GHz was equipped with a GeForce 6800 Ultra graphics card, not standard equipment. The DualCore 2.0 had a two-drive RAID-0 volume so the disk test is better than normal.

CPU Test:
2.3 Dualcore: 114,32
2.0 Dualcore: 101,55
2.5 Dual: 122,25

Thread test:
2.3 Dualcore: 113,74
2.0 Dualcore: 96,91
2.5 Dual: 125,90

Memory test:
2.3 Dualcore: 121,99
2.0 Dualcore: 110,32
2.5 Dual: 103,73

Quartz graphics:
2.3 Dualcore: 126,64
2.0 Dualcore: 107,07
2.5 Dual: 125,76

Open GL:
2.3 Dualcore: 135,38
2.0 Dualcore: 113,27
2.5 Dual: 125,63

User Interface:
2.3 Dualcore: 121,58
2.0 Dualcore: 118,98
2.5 Dual: 99,94

Disk Test:
2.3 Dualcore: 66,0
2.0 Dualcore 82,3 (2st harddrives RAID-1)
2.5 Dual: 69,3

TOTALS:
2.3 Dualcore: 108,7 (winner!)
2.0 Dualcore: 103,1
2.5 Dual: 105,9

As you can see the 2.3 GHz Dual Core machine is marginally faster than a water-cooled 2.5GHz Dual G5 with a souped-up graphics card. The largest difference is in memory performance, not in the actual processors according to our tests with Xbench. We want to point out that this testing method isn't completely failsafe but should mostly be seen as a hint of the new machine's performance.

Conclusion
The Power Macintosh G5 is better than ever and this is likely the last major update that we will see before the transition to Intel- processors. Apple has polished the details and the new processors gives some extra power. Because the exterior is largely exchanged this feels more like a "speedbump" even if the processor-switch is more significant than that.

Performance-wise, one Dual Core processor doesn't make for a large difference compared to two old G5 processors. We predict that the new Quad 2.5GHz Powermac will make for a performance increase of 70% or more.

New: Pictures of new Powerbook G4 with 1680x1050 display

Editor:
Martin Björnström
martin@bjornstrom.se

Photography:
Mats Björnström
mats@bjornstrom.se

Translation:
Mats Björnström
mats@bjornstrom.se

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