So I have a Power Mac G4 MDD I just got recently specifically for running Mac OS 9 at maximum potential and I was wondering something about PCI bus speeds and if there is only one PCI card in there would it direct all PCI bandwidth (64 bit at 33mhz according to everymac= 266MB/sec) to the one card if it demanded that much or if each of the slots run separately? I want to get a SATA card capable of booting Mac OS 9 and connect however many SSDs in RAID 0 to saturate the bandwidth of the card (since the only SATA cards that are capable of booting Mac OS 9 would have ports with a maximum speed of 1.5gb/sec each equating to needing around 3 SSDs) but I want to see if getting 1 card or 4 would give me the maximum speed. I know that this may not really make a noticeable difference due to other factors of the hardware but I just want to see what raw speed I can max it out with. Also I assume that AGP is not on the PCI bus but connected directly to the AGP controller that goes to the northbridge which shares the 167mhz 64 bit bus (2GB/sec) with the CPU and RAM so that wouldn't influence the PCI potential. Also the reason I would prefer this method is because there are 3 PATA busses on the board that add up to 200MB/sec in total bandwidth and I would have to buy multiple SATA to 3.5" PATA adapters which is fine but having this method would be nicer. I would use a SCSI card which I happen to have but I haven't seen any SATA to SCSI adapters nor any SCSI SSDs but I think my card is Ultra SCSI 320 so at 320MB/sec that should max out the PCI bus. Any ideas on what I should use?
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Question about conventional PCI
- Thread starter iPhoneguy404
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Probably an emulator on modern Macs can run macOS 9 faster than real hardware - except for 3D acceleration and games may have problems.
Which Power Mac G3 MDD do you have? There's a block diagram in Apple's Power Mac G4 document.
Power Mac G4 - Wikipedia
Accelerated Graphics Port - Wikipedia
PCI - Wikipedia
I think for PCI (266 MB/s) there's only one bus for the non-AGP slots and other devices - all cards are connected to the same bus. One card can take all the bandwidth if no other cards are doing anything.
Each SATA I drive can do 150 MB/s so maybe you can raid two or three of them together to saturate the PCI bus. I don't think it will matter how many SATA cards you use since they're all connected to the same bus.
AGP is a separate bus (1066 MB/s for AGP 2.0 4x) ("supporting peak transfers of 512 MB/s" according to the Apple Power Mac G4 doc). But both the PCI and AGP buses must connect to the Max bus (system bus) with the same connection (133 or 167 MHz 64 bit = 1066 or 1333 MB/s; where do you get the 2 GB/sec from?).
Two of the PATA buses are behind the PCI bus (according to the Apple Power Mac G4 doc). Those add up to 16.7 MB/s + 66 MB/s = 82.7 MB/s. One of the PATA buses (100 MB/s) is behind the Max bus.
So for max RAID, you have a couple options:
1) 2 or 3 SATA connected to PCI = max 266 MB/s
2) add some PATA in the mix:
2a) 100 MB/s PATA + 100 MB/s x 2 SATA = 300 MB/s
2b) 88.8 MB/s PATA + 88.8 MB/s x 3 SATA = 355 MB/s
2c) 50 MB/s x 2 PATA + 50 MB/s x 5 SATA = 350 MB/s
(drives in a RAID0 can only be as fast as the speed of the slowest drive multiplied by the number of drives)
Probably an emulator on modern Macs can run macOS 9 faster than real hardware - except for 3D acceleration and games may have problems.
Which Power Mac G3 MDD do you have? There's a block diagram in Apple's Power Mac G4 document.
Power Mac G4 - Wikipedia
en.wikipedia.org
Accelerated Graphics Port - Wikipedia
PCI - Wikipedia
I think for PCI (266 MB/s) there's only one bus for the non-AGP slots and other devices - all cards are connected to the same bus. One card can take all the bandwidth if no other cards are doing anything.
Each SATA I drive can do 150 MB/s so maybe you can raid two or three of them together to saturate the PCI bus. I don't think it will matter how many SATA cards you use since they're all connected to the same bus.
AGP is a separate bus (1066 MB/s for AGP 2.0 4x) ("supporting peak transfers of 512 MB/s" according to the Apple Power Mac G4 doc). But both the PCI and AGP buses must connect to the Max bus (system bus) with the same connection (133 or 167 MHz 64 bit = 1066 or 1333 MB/s; where do you get the 2 GB/sec from?).
Two of the PATA buses are behind the PCI bus (according to the Apple Power Mac G4 doc). Those add up to 16.7 MB/s + 66 MB/s = 82.7 MB/s. One of the PATA buses (100 MB/s) is behind the Max bus.
So for max RAID, you have a couple options:
1) 2 or 3 SATA connected to PCI = max 266 MB/s
2) add some PATA in the mix:
2a) 100 MB/s PATA + 100 MB/s x 2 SATA = 300 MB/s
2b) 88.8 MB/s PATA + 88.8 MB/s x 3 SATA = 355 MB/s
2c) 50 MB/s x 2 PATA + 50 MB/s x 5 SATA = 350 MB/s
(drives in a RAID0 can only be as fast as the speed of the slowest drive multiplied by the number of drives)
Thanks for the detailed reply! Initially I thought I got the 2GB/sec from the same way PCI bandwidth is calculated by multiplying the frequency by the bitrate (33mhz (actually 100/3) x 64 = 2133.333...mb/sec) and then dividing that by 8 to get 266MB/sec (well 266.666...MB/sec) but it turns out that I incorrectly calculated it and so using the same equation with the speed of the max bus at 167mhz which uses 64 bits as well (I assume 64 because my schematic for a PowerBook G4 showed that and they're both G4s) I get 167 x 64 / 8 = 1336MB/sec so that's the actual max speed between the northbridge/southbridge, CPU and RAM. (By the way where did you find the documentation for the Power Mac G4 MDD? Also my model is the 2003 single 1.25GHz which I'm going to upgrade the CPU to dual 1.42GHz) So anyways I guess that in order for it to have the most bandwidth to the SSDs through RAID 0, I would have to connect either 2 SATA drives on a 2 port PCI card at 150MB/sec each = 300MB/sec total but limited to 266MB/sec because of the PCI bus limitations or 3 SATA drives on a 4 port card saturating the limitations of the 266MB/sec limit and then adding a PATA to SATA adapter to the 100MB/sec PATA bus which would still push the PCI connection to the max at 266MB/sec but also increase the total to 355.2MB/sec. That sounds pretty good though another concern I've had was that OS 9 has a partition limit of 190GB I think or maybe it was 200GB so the idea is to get just enough storage space total to only have to make one partition but as big as it can be that would allow Mac OS 9 to boot. So since the speeds of the drives themselves are pretty much only going to be limited by the speed of however much bandwidth would be dedicated to each drive which in this case would be at most 88.8MB/sec, I'm pretty sure that there wouldn't be any difference using different sized SSDs which in order to get up to that limit I would have 2x 64GB and 2x 32GB drives to get me a total of 192GB and after formatting it should be less than 190GB as far as OS 9 would see and so I would connect one of the 64GB drives to a SATA to PATA adapter and the rest to 3 ports on the SATA card which I found out the most popular one is a SeriTek1V4 which is Mac OS 9 bootable but sadly very rare. So I would probably settle with 2x 2 port cards since the other one is the only one I can find with 4 ports that supports OS 9. I found that there are cards which would work but need to be flashed with certain firmware. The chipsets that have potential are the sil3112 which supports 2 ports, and the Sil3512 which supports 4 ports but mainly the extra 2 are esata which isn't really helpful and in this case. But also I've found that flashing firmwares to them requires the ROM to be upgraded to a larger size if putting on support for both OS 9 and OS X but I really only need OS 9 support.
Remember that none of our numbers takes into account PCI or SATA or whatever bus protocol overhead.
What RAID software would you use for Mac OS 9? I forget what options were available then. In OS X we would use Disk Utility.app to setup a software RAID.
What RAID software would you use for Mac OS 9? I forget what options were available then. In OS X we would use Disk Utility.app to setup a software RAID.