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BARE FEATS - real world Mac speed tests

"BARE facts on Mac speed FEATS"
Rob-ART, Main Mad Scientist (aka Dr. Frankenstein)
Bet-TAY, Special Features Edtior (aka Frau Blucher)

New Dual-Core
and Quad-Core G5/2.5 Power Macs

Originally posted October 21st, 2005, by rob-ART morgan, mad scientist

NOTE: Since we posted this briefing, we've been able to assemble some CPU performance test results and 3D Game test results for the Quad-Core.

We've done some research while waiting to test the new Dual-Core and Quad-Core G5 Power Macs Apple introduced recently. Here's what we've gathered so far...

"What kind of memory should I get, ECC or non-ECC?"
There's a helpful article on the Apple site that explains what ECC memory does. It discusses how the Xserve with ECC memory uses Server Monitor to collect stats on the number of errors made by each memory module. ECC memory can handle one bit errors without crashing the app or system. But with multiple bit errors and "kaboom" -- no matter what kind of memory you have.

ECC memory will NOT make your G5 go faster -- or slower.

"Should I get more expensive, higher speed memory with lower latency?"
Apple ships the Power Macs with CAS 4 PC2-4200 memory. We tried the lower latency CAS 3 memory. None of our benchmarks ran any faster.

Apple says, in addition to moving from DDR 400MHz memory to DDR2 533MHz, the memory controller has been made for efficient than the previous model of G5 Power Mac, increasing the throughput to 8.5GB/s versus 6.4GB/s.

"Apple lists the nVidia GeForce 7800 GT as a CTO option on the Power Mac Specs and Graphics page but it's not on the Online Store drop down ordering menu." That was fixed on October 26th, 2005. You can now order the GeForce 7800 GT with your new G5 Power Mac for as little as $350 extra!

I believe the 7800 GT will end up being the most popular graphics card option since it provides the most bang for the buck. Apple's own Power Mac Graphics page shows it to be only slightly slower than the much more expensive Quadro FX 4500.

I did some testing on Quadro FX 3400 cards and GeForce 6800 Ultra PCIe cards on a Windows PC a few months ago. The GeForce was quicker running 3D games (Halo and Doom 3) and benchmarks that were pixel intensive (3DMark, OpenMark). The Quadro excelled at polygon intensive benchmarks (specVIEWperf).

One of our readers (Mark Wilkins) reminded us that the Quadro FX 4500 has additional features that are not present on either GeForce card. These include hardware support for anti-aliased points and lines, accelerated clip planes, and two-sided lighting -- features important to advanced design and visualization applications. It also has an integrated stereo 3D port. For those users who are considering the purchase to run software like Maya (which only supports hardware rendering on the Quadro cards), the Quadro may well be worth the extra money.

Some may choose the Quadro since it supports dual 30" Cinema displays -- the only currently shipping PCIe card that does. It also has 512MB of DDR3 memory. But if you are choosing the Quadro just to support dual 30" Cinemas, but don't need the advanced features, read the "Brainstorm" in the box below.

BRAINSTORM: Rob Reuss emailed me an interesting idea. Why pay $1650 for the Quadro FX 4500 graphics card in your new G5 Power Mac just in order to drive two 30" Cinemas? The GeForce 6600 and 7800 GT each support a single 30" Cinema. You have spare PCI Express slots. Why not get two cards? Put the GeForce 7800 GT in the 16 lane PCIe slot and the GeForce 6600 in the 8 lane PCIe slot. Make the display on the 7800 GT the primary. That way, when you run a demanding 3D app that takes over the screen, it will be running off the faster card in the fastest slot. This alternate scenario doesn't use more slots because the Quadro FX 4500 uses up two slots with it's "fat" heatsink. But here's the kicker: The cost of getting the GeForce 7800 GT is $350 if added initially as CTO option. The 6600 is available as a kit for $200. So for one-third the price of the single Quadro FX 4500, you have dual 30" Cinema support and a total of 512MB video memory.

"Why isn't Apple supporting SLI mode with adjacent 16 lane PCI Express slots?"
That scenario was part of my daydream, but when I ran tests on a dual-core AMD machine in SLI mode, it produced only a 21% gain in Doom 3 and a 20% gain in Halo. Plus not all apps are not SLI aware. Those findings might explain why Apple wasn't too concerned about offering SLI mode.

For those of you who aren't familiar with the term, "SLI" stands for "Scalable Link Interface" where special edge connectors on the top of PCI Express graphics cards enable you to link adjacent cards using a special jumper, thereby providing scalability and increased performance.

"I heard that any PCI Express graphics card will work in the new G5 Power Mac -- not just those sold by Apple. Is this true?"
It would be great if this were true.

If you go to the specifications page for the GeForce 7800 GTX on the nVidia site, it does list Mac OS X as a Supported OS (bottom right). But if you go to the drivers page, it only lists Windows drivers. In other words, when they say Mac OS X is supported, that means "by Apple only with proprietary drivers and firmware."

ATI has one "PC and Mac" compatible card (Radeon 9600 Pro 4X). They said it was tricky putting firmware for both platforms in the card. Requires a big ROM and careful programming. Supporting multiple platforms is not a slot issue (PCIe vs AGP) but a firmware issue as we see it.

"All PCI Express slots? What do I do with all my PCI-X and PCI cards? And when is someone coming out with PCI Express versions of SATA II?"
I'm getting a lot of email from frustrated would-be Dual-Core and Quad-Core G5 Power Mac owners like the one quoted above.

The reason Apple shifted to PCI Express is simple: bandwidth. The 16 lane PCI Express slot has a concurrent bandwidth of 4GB/s each direction (compared to 2.1GB/s for 8X AGP). The 8 lane clocks 2GB/s per direction. The 4 lane is rated at 1GB/s. The fastest previous PCI-X slot (133) ran at 1GB/s.

Most high end Windows PCs I've tested recently come with both PCI Express slots and PCI-X slots. That's probably because they know pro users often have an investment in "legacy" cards. I think Apple should have configured the new G5 with dual PCI-X 133 slots and dual 16 lane PCI Express slots with SLI support.

Apple's actually offers a solution for those with a large investment in PCI-X cards. They suggest that they buy April's G5/2.7GHz Power Mac. which they are either still building or still have piled up in the warehouse. Apple has a special page telling about it.

For more technical information on PCI Express, visit the Special Interest Group site.

"Where's the performance graphs?"
We have two pages with test results as of November 11th:

1. Dual-Core G5/2.0GHz Power Mac vs Single-Core Dual G5/2.0 Power Mac

2. Quad-Core G5/2.5GHz Power Mac vs Single-Core Dual G5/2.5 Power Mac

Apple Online Store


When ordering products from Apple Store USA, please click THIS TEXT LINK or any Apple display ad as your "portal" to the online store. In so doing, you help to support Bare Feats. (DON'T LIVE in the USA? See links for Apple online stores in other countries.)

You can custom order G5 Power Macs from Small Dog Electronics. For refurbished, reconditioned, open box (as well as new) G5 Power Macs, check with Small Dog and Power Max. Check also at the Apple SPECIAL DEALS section for factory refurbs and other specials.

Other World Computing has very good prices for both 2GB and 4GB PC2-4200 non-ECC memory kits for the Dual-Core and Quad-Core G5 Power Mac. The 2GB (1GB x2) kit is $175. The 4GB (2G x 2) kit is $530. Both kits are in stock.

Some of you have asked about ECC memory. ECC memory can handle one bit errors without crashing the app or system. But with multiple bit errors and "kaboom" -- no matter what kind of memory you have. It isn't slower than non-ECC memory -- nor is it faster. If you want to go with ECC for your Quad or Dual-Core, OWC has the 2GB ECC kits for $340 and the 4GB ECC kits for $675.

Some of you have asked which "older" G5 Power Mac models are most desirable. I recommend getting a model with 8 memory slots, 100/133MHz PCI-X slots, and 600W Power Supply. The table below gives the model number, etc., of these most desirable older G5s.

Model Number
clock speed
intro date
June 2003
June 2003
November 2003
June 2004
June 2004
April 2005
April 2005

All other G5 (AGP) models have only 4 memory slots, 33MHz PCI slots, 450W Power Supply, and slower frontside bus speeds. If you can't find the model you want at Apple's Special Deals page, Small Dog's site, or Power Max's site, go to Froogle.com and search on the model number.


SATA II -- HighPoint Technologies has posted Mac drivers for their RocketRAID 2320 PCI Express 4X SATA II RAID host adapter (8 internal ports, RAID 0, 1, and 5 support). We've tested it. It works as advertised. Won't let your Quad-Core (or Dual-Core) go to sleep, though.

FIREWIRE 800 -- Aaxeon has a FireWire 800 PCI Express card. We tried it. It works on the Quad-Core, but the write speed are one-half of what we get on the built-in factory FireWire 800 port. There are also sleep issues.

SCSI -- Atto Technology is shipping an Ultra 320 SCSI PCI Express card (UL5D). You can buy it direct from their ATTO store.

Serial Attached SCSI -- Adaptec has a PCI Express version of their Serial Attached SCSI host adapter. I've heard they are planning a Mac verson, but Mac OS X is not listed as one of the supported Operating Systems.

FIBRE CHANNEL -- Apple has posted a link to their PCI Express version of their Fibre Channel card. I expect ATTO's new 4-Gigabit Fibre Channel PCI Express card to be offered in a Mac version.

VIDEO CAPTURE -- Blackmagic Design's "World's First PCI Express Capture Card" is now officially compatible with the Dual-Core and Quad-Core G5 Power Macs. AJA has a PCI Express version of their Kona card called the LHe.

AUDIO PRODUCTION -- Digidesign is working on a PCI Express version of Pro Tools HD scheduled to ship before the end of the year.

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