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Mac Forum / Country Specific / UK Mac Group / May 2008PCI cards for a G5...
I think I'm having trouble with the USB hub I have here, so on the hunt for a replacment. I'm considering a PCI card instead. However, the last one I got (a generic PC card) did work, but caused sleeping problems. Doing a bit of research makes me wonder, my G5 has the PCI-X slots, how backwards compatible are these slots? They are specified at 100MHz for slots 2 & 3, and 133MHz for slot 4. The manual only gives data for fitting slower cards into the standard PCI slots at 33MHz, stating that 66MHz cards can be used as long as they are capable of runing at 33MHz. No such information seems to be available for the PCI-X slots. Most of the USB cards I can find are only 33MHz, although they are 3.3v, which is the preferred voltage on the G5. Anybody got a clearer idea of what cards can actually be used in the PCI-X slots? Can they switch down to lower MHz cards? Cheers.  SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> >I think I'm having trouble with the USB hub I have here, so on the hunt >for a replacment. I'm considering a PCI card instead. However, the last [quoted text clipped - 3 lines] >backwards compatible are these slots? They are specified at 100MHz for >slots 2 & 3, and 133MHz for slot 4. The PCI-X standard mandates backwards compatibility with ye olde 33MHz cards. It doesn't mandate 5V compatibility though - and that is shown by the physical slot cutouts, a 5V card won't fit into a 3.3V-only slot. >Anybody got a clearer idea of what cards can actually be used in the >PCI-X slots? Can they switch down to lower MHz cards? So the answer is "they damn well should do or they're not PCI-X", but there's always the possibility that Apple might have Thought Differently. Cheers - Jaimie Signature"If I'd been the Green Goblin, I'd have got a big bath and lured Spiderman into it, and being a spider he wouldn't have been able to climb out. Muahahaha." -- Paul Clark, urs > So the answer is "they damn well should do or they're not PCI-X", but > there's always the possibility that Apple might have Thought > Differently. It is worth reading the Developer Note for the appropriate model Mac to get this kind of information. Start about here: <http://developer.apple.com/hardwaredrivers/> At some point you'll start to curse Apple for not making it easy to distinguish between versions of identical-looking kit... Cheers, Chris > > So the answer is "they damn well should do or they're not PCI-X", but > > there's always the possibility that Apple might have Thought > > Differently. Well, I did wonder. It's only because, a) I had trouble using a standard PCI 33MHz card, and b) they don't mention the lower speeds for PCI-X in the manual, but they do for PCI. > It is worth reading the Developer Note for the appropriate model Mac to > get this kind of information. Start about here: [quoted text clipped - 3 lines] > At some point you'll start to curse Apple for not making it easy to > distinguish between versions of identical-looking kit... Thanks, I'll have a go at that then. SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> >> So the answer is "they damn well should do or they're not PCI-X", but >> there's always the possibility that Apple might have Thought [quoted text clipped - 7 lines] >At some point you'll start to curse Apple for not making it easy to >distinguish between versions of identical-looking kit... Heh. Still, take the MSKB - they always have "This article applies to..." lists, but they don't update the bloody things for later releases of software/OS so you still can't trust them. If Apple did the same thing with their notes, I'm sure they wouldn't do any better. http://developer.apple.com/qa/qa2001/qa1307.html states that "These slots are compliant with the PCI-X Addendum to the PCI Local Bus Specification, rev. 1.0b." which means they will talk 33MHz, 3.3V. Cheers - Jaimie Signature"I love the way that Microsoft follows standards. In much the same manner as fish follow migrating caribou." - Paul Tomblin, ASR > >> So the answer is "they damn well should do or they're not PCI-X", but > >> there's always the possibility that Apple might have Thought [quoted text clipped - 16 lines] > slots are compliant with the PCI-X Addendum to the PCI Local Bus > Specification, rev. 1.0b." which means they will talk 33MHz, 3.3V. Thanks Jaimie. That's cleared that up then :-). Just wanted to be sure before purchasing another card. SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> Ok, so I can no identify suitable PCI cards for the G5 - the 5v and 3.3v ones are quite clearly obviouse now. There are shed loads on eBay, but I'm still wary of these. However, I'm also sure my current (Trust) hub is playing up too. I need to plug in at least 6 extra USB devices. One of these is my UPS, which obviously needs USB power after a power failure, so needs to be plugged into the Mac directly really. If I went the PCI card route, are there any problems with fitting two identical cards, or should I fit two from different vendors (say a VIA one and an NEC one). Cheers SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> > Ok, so I can no identify suitable PCI cards for the G5 - the 5v and 3.3v > ones are quite clearly obviouse now. [quoted text clipped - 9 lines] > identical cards, or should I fit two from different vendors (say a VIA > one and an NEC one). I wouldn't have thought that would be a problem. What sort of current is each of your devices going to draw from the USB port, and how much current can a single PCI card provide? Cheers, Chris [..] > > If I went the PCI card route, are there any problems with fitting two > > identical cards, or should I fit two from different vendors (say a VIA [quoted text clipped - 3 lines] > is each of your devices going to draw from the USB port, and how much > current can a single PCI card provide? I was thinking more of the identity of the cards. Current shouldn't be a problem, most things are self powered. The media card reader, iMic, EyeTV Hybrid and keyboard are USB powered. I could easily share those between the cards and the original ports. SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> >I need to plug in at least 6 extra USB devices. One of these is my UPS, >which obviously needs USB power after a power failure, so needs to be >plugged into the Mac directly really. Wait, what? The UPS will be running of its own battery, as will (presumably) the Mac. It certainly won't be pulling power from the Mac via USB. Cheers - Jaimie SignatureWomen's breasts are like electric train sets. They're meant for kids, but usually it's the fathers who wind up playing with them. > >I need to plug in at least 6 extra USB devices. One of these is my UPS, > >which obviously needs USB power after a power failure, so needs to be [quoted text clipped - 3 lines] > (presumably) the Mac. It certainly won't be pulling power from the Mac > via USB. No, it'll need power to the USB just for communications, otherwise the Mac doesn't know it's on UPS power does it. If I stick it through a hub that has its own power, it'll lose comms when the power to the USB hub fails (the hub isn't on a UPS powered socket), and thus the G5 won't know to shutdown before the battery runs down. The best way to ensure this, is to connect the USB link for the UPS to a USB port that will stay live when only the UPS is powering the system - i.e. a built-in USB port on the G5. SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> >> >I need to plug in at least 6 extra USB devices. One of these is my UPS, >> >which obviously needs USB power after a power failure, so needs to be [quoted text clipped - 6 lines] >No, it'll need power to the USB just for communications, otherwise the >Mac doesn't know it's on UPS power does it. Yes, it will - it's not a dead-man-switch connection, the UPS actually talks data to the computer. Battery life, mains status, depends on what the UPS mfr makes available. > If I stick it through a hub >that has its own power, it'll lose comms when the power to the USB hub >fails (the hub isn't on a UPS powered socket), and thus the G5 won't >know to shutdown before the battery runs down. (I would recommend putting the USB hub on a UPS-powered socket, since it hardly draws any juice and at some point you'll discover that you've got your mouse and/or keyboard through it, thanks to Murphy) >The best way to ensure this, is to connect the USB link for the UPS to a >USB port that will stay live when only the UPS is powering the system - >i.e. a built-in USB port on the G5. That's definitely true, but for not for the reason you have in the first para. Cheers - Jaimie Signature"I have an asteroid named after me. Isaac Asimov's got one too. It's smaller and more eccentric." -- Arthur C. Clarke > >> Wait, what? The UPS will be running of its own battery, as will > >> (presumably) the Mac. It certainly won't be pulling power from the Mac [quoted text clipped - 6 lines] > talks data to the computer. Battery life, mains status, depends on > what the UPS mfr makes available. So if I don't plug in the USB cable, my Mac will still know it's connected to a UPS? > > If I stick it through a hub > >that has its own power, it'll lose comms when the power to the USB hub [quoted text clipped - 4 lines] > it hardly draws any juice and at some point you'll discover that > you've got your mouse and/or keyboard through it, thanks to Murphy) Hmm, good point. > >The best way to ensure this, is to connect the USB link for the UPS to a > >USB port that will stay live when only the UPS is powering the system - > >i.e. a built-in USB port on the G5. > > That's definitely true, but for not for the reason you have in the > first para. I still don't see why not? SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> >> >> Wait, what? The UPS will be running of its own battery, as will >> >> (presumably) the Mac. It certainly won't be pulling power from the Mac [quoted text clipped - 9 lines] >So if I don't plug in the USB cable, my Mac will still know it's >connected to a UPS? Let's start again... You have a UPS. You plug the Mac into the UPS power outlet. The Mac is now protected from short-term mains outages. You also connect the USB cable from the UPS to the Mac. The USB cable allows the UPS to inform the Mac when the power is out, by sending a data packet that the Mac is listening for. It also allows the Mac to ask the UPS how much battery is available, and so on. This can be a direct cable, or indirect through a hub. The mains power goes out. If a hub was in use, and it was not powered from the UPS, the Mac will now no longer be able to monitor/recieve info from the UPS - this would generally be non-optimal but not fatal. If the USB comms between UPS and Mac are still in place, the UPS sends a packet over USB to the Mac saying "I've switched to battery mode". The Mac then does whatever comes naturally - usually this would be to not worry until the UPS reports less than 10% battery left, at which point to shut down. So at no point does the UPS require 5V@.5A from the Mac's USB cable to function. Only the data transfer wires are used. I suppose the UPS *could* attempt to monitor when the Mac has powered down by watching the USB 5V wire, but I've never seen one that did - and the UPS doesn't care anyway. It wouldn't be reliable either, since most mains-powered computers hold 5V on the USB power wire even when they're nominally powered off. >> > If I stick it through a hub >> >that has its own power, it'll lose comms when the power to the USB hub [quoted text clipped - 15 lines] > >I still don't see why not? Hopefully that clears it up! Cheers - Jaimie Signature"Once you adopt the unix paradigm, the variants cease to be a problem - you bitch, of course, but that's because bitching is fun, unlike M$ OS's, where bitching is required to keep your head from exploding." - S Stremler in afc [..] > >So if I don't plug in the USB cable, my Mac will still know it's > >connected to a UPS? [quoted text clipped - 3 lines] > You have a UPS. You plug the Mac into the UPS power outlet. The Mac is > now protected from short-term mains outages. Yup. > You also connect the USB cable from the UPS to the Mac. The USB cable > allows the UPS to inform the Mac when the power is out, by sending a [quoted text clipped - 3 lines] > > The mains power goes out. Yup. > If a hub was in use, and it was not powered from the UPS, the Mac will > now no longer be able to monitor/recieve info from the UPS - this > would generally be non-optimal but not fatal. So far. > If the USB comms between UPS and Mac are still in place, the UPS sends > a packet over USB to the Mac saying "I've switched to battery mode". > The Mac then does whatever comes naturally - usually this would be to > not worry until the UPS reports less than 10% battery left, at which > point to shut down. Right. So if the USB has lost communication, how does the Mac know that there's only X% of battery left, or that it's been running on UPS for X-minutes? I guess this might depend on the hub, and whether it'll transmit data without being powered. I don't think the one I have does so. > So at no point does the UPS require 5V@.5A from the Mac's USB cable to > function. Only the data transfer wires are used. [quoted text clipped - 4 lines] > most mains-powered computers hold 5V on the USB power wire even when > they're nominally powered off. Erm, yes, actually I know the UPS doesn't care what's happening, it the Mac I'm interested in. How does it know what's going on if the USB link is dropped? Obviously it might know the power was restored if peripherals regained connection. SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> > [..] >> >So if I don't plug in the USB cable, my Mac will still know it's [quoted text clipped - 32 lines] > there's only X% of battery left, or that it's been running on UPS for > X-minutes? IT DOESN'T !! IT DOESN'T !! IT DOESN'T !! IT DOESN'T !! Hence the need to maintain the communication between the UPS and the Mac. Either power the USB hub from the UPS or connect the UPS signal cable DIRECT to a USB port on the Mac. -- Graham J > IT DOESN'T !! > IT DOESN'T !! [quoted text clipped - 4 lines] > Either power the USB hub from the UPS or connect the UPS signal cable DIRECT > to a USB port on the Mac. Yes, that's how I was understanding it. SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> >> IT DOESN'T !! >> IT DOESN'T !! [quoted text clipped - 6 lines] > >Yes, that's how I was understanding it. Jolly good, then all is well. Cheers - Jaimie SignatureMy swerver room, my patch panels. By the time they figure out why none of the ports on their floor box work anymore I'll be done, dusted and down the pub with a pint of something brewed with yeast that was smarter than they are. -- Matt S Trout, asr > Ok, so I can no identify suitable PCI cards for the G5 - the 5v and 3.3v > ones are quite clearly obviouse now. [quoted text clipped - 9 lines] > identical cards, or should I fit two from different vendors (say a VIA > one and an NEC one). I'd go for a hub if I were you. I've had trouble from plug-in cards on Macs. Don't trust 'em at all. Don't like kernel panics. Rowland. SignatureRemove the animal for email address: rowland.mcdonnell@dog.physics.org Sorry - the spam got to me http://www.mag-uk.org http://www.bmf.co.uk UK biker? Join MAG and the BMF and stop the Eurocrats banning biking > > Ok, so I can no identify suitable PCI cards for the G5 - the 5v and 3.3v > > ones are quite clearly obviouse now. [quoted text clipped - 14 lines] > I've had trouble from plug-in cards on Macs. Don't trust 'em at all. > Don't like kernel panics. Aye, I've had trouble with waking from sleep, although no kernel panics from them (I'm not denying the possibility though). However, I've also had trouble with hubs too - which is the current situation I have. I have recently been getting bother with my media card reader not working correctly, where it will load a card into the OS, but then refuse to download any images. If I plug it directly into a built-in port, it works OK. SignatureAndy Hewitt <http://web.mac.com/andrewhewitt1/> |
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