View Full Version : Which macs have 64 bit/66mhz slots?

04-09-2001, 01:57 AM
I was just looking at apples new offerings, and I noticed the towers now have 32bit/66mhz pci slots.

Anyone got time to review all the models that have 64 bit/66mhz slots, past and present?

Is it just me, or did the older macs have faster pci buses???


04-09-2001, 10:37 AM
from Apple's site
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> The other four are 64-bit 33MHz PCI slots with enhanced performance capabilities (maximum throughput has been increased from 100 up to 215 megabytes per second).<HR></BLOCKQUOTE>

They are using a revised UNi-North bridge chip which is faster than the previous G4. The controler is now running at 133 MHz.


04-09-2001, 11:42 AM
Are you sure on this? I would have sworn the last generation of macs had 64 bit/66 mhz slots, and Magician was getting up to 168 MB/sec with 8 x-15's...
QuickBench¬? 1.0.1 Test Results File
©2000 Intech Software Corp.
Test file created on Wednesday, July 12, 2000 at 12:48:29 AM
Test Volume name: 8xST318451LW_DCUL3D

Xfer Size Sequential Read Sequential Write Random Read Random Write

1 KByte 437.407 KB/sec 566.283 KB/sec 408.764 KB/sec 584.659 KB/sec
2 KBytes 4.467 MB/sec 1.192 MB/sec 2.868 MB/sec 1.189 MB/sec
4 KBytes 6.189 MB/sec 2.392 MB/sec 5.738 MB/sec 2.451 MB/sec
8 KBytes 6.462 MB/sec 4.621 MB/sec 10.319 MB/sec 5.000 MB/sec
16 KBytes 9.344 MB/sec 8.963 MB/sec 6.283 MB/sec 8.132 MB/sec
32 KBytes 8.737 MB/sec 15.719 MB/sec 35.994 MB/sec 15.396 MB/sec
64 KBytes 12.946 MB/sec 26.791 MB/sec 27.375 MB/sec 13.935 MB/sec
128 KBytes 45.882 MB/sec 48.493 MB/sec 23.990 MB/sec 25.773 MB/sec
256 KBytes 96.399 MB/sec 74.551 MB/sec 43.124 MB/sec 51.179 MB/sec
512 KBytes 143.209 MB/sec 105.959 MB/sec 79.088 MB/sec 94.936 MB/sec
1 MByte 168.098 MB/sec 130.774 MB/sec 123.611 MB/sec 120.135 MB/sec

None the less, has anyone done tests with the new chipsets, to see how fast they actually are???


The above came from the ftp archives

04-09-2001, 12:31 PM
That quote was from the Apple site. I'll go through the tech doc (if I can find it).


04-09-2001, 12:39 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Expansion slots 2, 3, and 4 accommodate 33¬?MHz PCI cards with either 32-bit or 64-bit address and data buses. The PCI cards can use power at +5¬?V, +3.3¬?V, or both. The slots accept standard 6.88-inch and 12.283-inch PCI cards as defined by the PCI Local Bus Specification , Revision 2.1. The cards are required to use the standard ISA fence described in the specification.<HR></BLOCKQUOTE>

That is from the APple tech docs. They do list them as 33/66 bit addressing.


04-09-2001, 06:02 PM
Thanks Jorge

For some reason I thought the older macs had 64 bit/66mhz slots. Guess I was wrong.
The fast slots must be 64 bit/33mhz.

Now, is the atto card capable of running in a 64bit/66mhz slot, and a 64 bit 33/mhz slot???



04-09-2001, 07:03 PM
I think there was a model prior to AGP, that had one faster PCI slot for the video card.

04-09-2001, 07:38 PM
Hi Louie

I thought the last generation mobos had two 64 bit/66mhz pci slots.

Oh well, chalk it up to delusions.


04-09-2001, 08:26 PM
I think the 66 MHz slot was the faster graphics slot in the B&W G3s.


04-09-2001, 08:57 PM
j is right, the graphics slot for the ATI card in the G3 B&W was 32-bit, 66 MHz.
The other PCI slots in the Yosemite and newer are all 64-bit, 33 MHz
Previous Powermacs all had 32-bit, 33 Mhz PCI slots
Apple has never offered a 64-bit, 66 MHz PCI slot of any kind

As I understand it,
2X AGP uses double transition clocking to net 64-bit x 33 MHz in a 32-bit, 33 MHz slot
4X AGP uses double transition clocking to net 64-bit x 66 MHz in a 32-bit, 66 MHz slot

04-10-2001, 03:20 PM
Don't know why I thought it was a 64bit/66mhz bus.

Just got done reviewing the comments Magician wrote on the ATTO card, and I'm happy that it does work on 64 bit/66 mhz server boards.

Thanks again for the help


04-10-2001, 07:05 PM
Hey greg,

Yeah, personally, that's why I recently got an ATTO UL3D, even though I'm only using it in a 9600 now. It's 64-bit, 66 Mhz capable and works with OS X, whenever I get around to it.

04-14-2001, 08:09 AM
man, I have missed a lot the past couple of days.

remember: the 66MHz slot in the Yose was 32-bit, 3.3v,only. It only differed from the other slots in its clock speed and its width.

the others are 64-bit, 33MHz, 3.3v OR 5v.

supposedly, it is supposed to be possible to stuff an ATTO Ultra3 in that 66MHz slot. I have not done so myself. It was reserved for the Rage 128 video card. I actually have a couple of those boards laying around here. While they are 3.3v, they are supposed to also work in 5v PCI slots....sometimes they actually do.

all my testing has been using ATTO boards and others in the 64-bit 33MHz slots. I leave the video cards alone, for the most part.

in the newer machines....remember, you have AGP. All the PCI slots are 64-bit, 33MHz, 3.3v and 5v.

04-19-2001, 05:45 PM
Hi Magician:

Cost preformance wise, and driver support for os X, I am looking at a Miles 2 vs. Adaptec 2940U2 that you have on special.

Your sales pitch on the 2940 is very good, and I figure since the Grackle chip is maxed at 75 MB/sec, why not get a 500 card out, and use it in a machine that might run another 50 MB/sec faster?

Any other suggestions for LVD cards for a G3 333?



04-19-2001, 05:51 PM
Just went over your sales pitch again. What do you mean by the adaptec cards being slow?
Do you have an oem version of the Miles 2, sans cables and software, since I have both, and, if so, how much is it?

email me if need be, or I might call, since this is a sort of hot item right now for me...