---------- Original message ---------- Subject: 64-bit question Date: Samstag 16 Oktober 2010N From: Arnel Tuazon <a.tua...@gmail.com> To: "G-List" <g3-5-list@googlegroups.com>
> I know my G5 is 64-bit (I have the late 2005 dual core PPC G5), but is > Leopard (10.5.9) 64-bit? Yes and no. The kernel is 32-bit, but it can run 64-bit applications. Tiger could also run 64-bit applications, but not in the GUI i.e. Aqua → only console applications can be 64-bit under Tiger. Since Leopard also a GUI application (Carbon, Aqua) can be 64-bit. Keep in mind, that 64-bit is only useful for >4 GB of memory. You also have to distinguish between system memory and application memory. * A 32-bit application will always be limited to use as much as 4 GB of memory (physical or virtual). A 64-bit application can use all the memory you've got. * A 32-bit kernel can handle more than 4 GB of memory, so the kernel is not the real issue here. > I've been looking on the net, but couldn't find a definitive answer. If you are really interested, read this article: http://arstechnica.com/apple/reviews/2007/10/mac-os-x-10-5.ars/6 Quote: “Apple has [with Leopard] gone 64-bit across the board, with two major exceptions. The first is the kernel itself, which remains 32-bit in order to maintain compatibility with existing drivers. …” Some more links: http://en.wikipedia.org/wiki/Mac_OS_X_Leopard http://www.appleinsider.com/articles/08/09/04/road_to_snow_leopard_twice_the_ram_half_the_price_64_bits.html > I was told that only 10.6+ is 64-bit. True, when including the kernel. Snow Leopard can boot into a 64-bit kernel also on desktop computers and laptops, when you hold down the keys “6” and “4” but the default kernel is still 32-bit. This is due to compatibility to existing applications. Kernel extensions (.kext) will only work with the right kernel, so 32-bit extensions require a 32-bit kernel. A lot of desktop applications require specific kernel extensions in order to function. Snow Leopards defaults to the 64-bit kernel on servers, since extensions are not so importaint there, but memory is! > If this is true is there an alternative OS that will run at 64-bit on the PPC G5? The only operating system I can come up with is Linux. There may be others though, like commercial Unices like AIX or so, but I'm not sure if they even run on a Power Mac. AmigaOS/MorphOS is also a PowerPC operating system, but I don't think it's 64-bit. Note that Linux has the same problem Mac OS X has when running a 64-bit kernel: extensions (Linux: kernel modules) will only run on the right kernel. For GUI applications 32-bit programs will require a 32-bit version library. So if your system is all 64-bit, you may not be able to run 32-bit programs at all. Of course, this is not so much of a real problem under Linux, since most applications are open source software anyway (and therefor 64-bit versions are possible with an estimated 99% of all open source software). > Not that I would install it, I was just curious if there was one. I had Gentoo Linux running on my Power Mac G5 “Late 2005” with its 16 GB of DDR2 memory. It was great, only that Linux support sucks on the G5. This is true for both 32-bit and 64-bit, since this doesn't make that much of a difference with Gentoo Linux anyway. Okay, it doesn't suck, but there are some bits and pieces that aren't supported or that just don't work yet. The biggest problem is support for the graphics card. Most Linux drivers (like the X11 graphics drivers radeon for ATI cards and nv/nouveau for nVidia cards) require a PC compatible BIOS from the graphics card, which is not present in Power Mac versions of these cards, since they are made to work on Open Firmware instead of a PC compatible BIOS. Another is that closed source Linux applications –like Adobe Reader, Skype, Flash Player to name just a few– don't work on PowerPC. They are only available for Linux/x86 and sometimes (like Flash), but not always, for amd64 (the 64-bit version of x86). Some minor bits of hardware is not (yet) supported, like the ECC memory/EDAC driver for the CPC945 chipset of the “Late 2005” G5 (PowerPC 970MP). > Thanks! Welcome! I hope that helped. Andreas aka Mac User #330250 -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
