spartango Posted July 23, 2008 Share Posted July 23, 2008 I installed Snow Leopard on a Macbook Pro (2.4 GHz core 2 duo "penryn"), and was surprised to find that it was running the 32 bit kernel despite the machine being 64-bit capable... uname -a showed the i386 kernel was running I really wanted to try the full 64 bit kernel and there exists no force64 kernel flag...After a bit of hacking I've figured out how to force 64-bit boot with Snow Leopard... --- EDIT: Due NDA issues/affiliations, can't have those instructions on the blog...so they're HERE: --- 0. Backup whatever kernel you're using. Just in case. 1. in a super user shell (or sudo) cd to / #lipo -remove i386 mach_kernel [you could specify the output file, but whatever. 2. Reboot -- Basically I removed the i386 kernel from the universal binary, causing it to select the remaining x86_64 kernel (can't choose PPC) and run it. Note that no 32-bit kexts work. good luck man lipo Link to comment Share on other sites More sharing options...
jnolla Posted May 19, 2009 Share Posted May 19, 2009 Care to share? Couldn't find the instructions on your Blog. Thx Link to comment Share on other sites More sharing options...
Adrian Fogge Posted May 19, 2009 Share Posted May 19, 2009 Previously, one was able to press the keys "6" + "4" on the keyboard on boot to force using the 64-bit kernel, or "3" + "2" to force using the 32-bit kernel. I haven't tried it in a *long* time, but I would assume that Apple hasn't removed this functionality in the later builds. ~Adrian Link to comment Share on other sites More sharing options...
Superhai Posted May 19, 2009 Share Posted May 19, 2009 It is still 6+4 to use 64 bit kernel in 10A354. Apple did also publish to the testers which machine supports 64 bit by default. Link to comment Share on other sites More sharing options...
Adrian Fogge Posted May 20, 2009 Share Posted May 20, 2009 The real question will be whether I could force a 32-bit kernel and make my DisplayLink graphics card work under Snow Leopard. I know that DisplayLink graphics cards do not work under the 64-bit kernel as no module has been written yet, and I am addicted to the whole 3 displays thing... While I *love* Snow Leopard's performance, I am much too tied to screen real estate to justify making the move on my primary laptop. Plus, what fun is having Snow Leopard set up on a Mini that I only ever VNC into??? ~Adrian Link to comment Share on other sites More sharing options...
computerbandgeek Posted May 25, 2009 Share Posted May 25, 2009 The 6 + 4 key combo doesn't seem to work for me, so I am interested in this hack but cannot find it on your blog Link to comment Share on other sites More sharing options...
fmac Posted May 26, 2009 Share Posted May 26, 2009 The 6 + 4 key combo doesn't seem to work for me, so I am interested in this hack but cannot find it on your blog Can you edit your "com.apple.boot.plist" try the kernel flag "-x64" for me it is working, but then I have a problem with dsmos.kext so only 32bit mode enable in 10A335f on my hakintosh Sorry for my english AUSTRIA - high montains, no kangurus Link to comment Share on other sites More sharing options...
Takuro Posted June 11, 2009 Share Posted June 11, 2009 I have a 2008 iMac with a Penryn and have to do the same thing to enable the 64-bit kernel. My main question is, why is Apple so determined not to let my iMac run 64-bit software? It even complains that "64-bit is not supported on your system" when I try to install Boot Camp drivers on Windows 7 x64. After hacking the installer MSIs, the drivers install fine! So what's the point? Why not just designate my system as supported out of the box? Link to comment Share on other sites More sharing options...
Ritsuka Posted June 11, 2009 Share Posted June 11, 2009 You can already run 64bit software in Leopard on your iMac, you don't need the new 64bit kernel to run 64bit software. Link to comment Share on other sites More sharing options...
Takuro Posted June 11, 2009 Share Posted June 11, 2009 Eh, yeah. I just figured that out. Running the kernel in 64-bit mode made some basic tasks like launching apps about 20% faster, but after that, the apps ran either in 32 or 64-bit mode regardless of which kernel is used. For some reason, since the kernel is part of a lower layer of the operating system, I thought everything running on the application level would be limited to a subset of whatever architecture the kernel was. I don't know how OS X is completely structured, but I guess that, if this isn't the case, Applications might have more direct access to hardware so they can use whatever architecture they need regardless of the kernel. Losing 32-bit extensions was a blow though. I can't stand my mouse's crazy acceleration unless USBOverdrive is loaded to help control it. Back to the 32-bit kernel for now. Link to comment Share on other sites More sharing options...
Yarrow Posted June 12, 2009 Share Posted June 12, 2009 Whether anyone got build 10A380 of Snow Leo (WWDC'09) successfully running on 64-bit kernel? If 'yes' - please share your method. I've tried every approach that i know: "6+4" keys, arch=x86_64 flag specified for both nvram and com.apple.Boot.plist, lipo command against mach_kernel. Nothing helps. Link to comment Share on other sites More sharing options...
Dnizzle Posted June 17, 2009 Share Posted June 17, 2009 I am also quite curious Link to comment Share on other sites More sharing options...
xor_2 Posted June 17, 2009 Share Posted June 17, 2009 it's funny cos on Hackintoshes it's only a matter od adding -x64 during boot but 64-bit kernel doesn't work cos we must use custom 32-bit only (atleast yet...) kexts I must use 32-bit dsmos.kext and applenforceata.kext and apple3com????.kext for network and get "Still waiting for root device..." in x64 mode (probably of lack 64bit applenforceata.kext) :censored2: Link to comment Share on other sites More sharing options...
bogdi1988 Posted June 17, 2009 Share Posted June 17, 2009 6+4 worked for me on my UMBP 15". it booted in 64-bit mode, but my keyboard would not work :-s maybe some problem with the 64-bit kext for keyboard.... i am running the 10A380 build. EDIT: i managed to boot into 64-bit mode. held 6+4 and it booted into 64bit. unfortunatelly, parallels does not run in 64-bit mode, so i can not run my windows 7 virtual machine... Link to comment Share on other sites More sharing options...
xor_2 Posted June 20, 2009 Share Posted June 20, 2009 @bogdi1988 Can U post Xbench scores in both 32 and 64 bit modes? Link to comment Share on other sites More sharing options...
loren1979 Posted July 11, 2009 Share Posted July 11, 2009 Hello all, Here is some information that was requested. Overall, slightly better memory performance, but slightly lower performance across the board. Still in beta - still press 6 and 4 (where available). 32bit: Results 199.63 System Info Xbench Version 1.3 System Version 10.6 (10A402a) Physical RAM 2048 MB Model MacBookPro5,5 Drive Type FUJITSU MJA2160BH FFS G1 CPU Test 160.47 GCD Loop 263.85 13.91 Mops/sec Floating Point Basic 127.17 3.02 Gflop/sec vecLib FFT 107.34 3.54 Gflop/sec Floating Point Library 252.72 44.01 Mops/sec Thread Test 294.84 Computation 389.98 7.90 Mops/sec, 4 threads Lock Contention 237.02 10.20 Mlocks/sec, 4 threads Memory Test 185.02 System 219.33 Allocate 302.81 1.11 Malloc/sec Fill 177.31 8621.35 MB/sec Copy 211.14 4361.10 MB/sec Stream 160.00 Copy 153.02 3160.52 MB/sec Scale 150.61 3111.65 MB/sec Add 169.51 3610.92 MB/sec Triad 168.76 3610.14 MB/sec Quartz Graphics Test 171.07 Line 150.50 10.02 Klines/sec [50% alpha] Rectangle 193.78 57.85 Krects/sec [50% alpha] Circle 165.27 13.47 Kcircles/sec [50% alpha] Bezier 175.28 4.42 Kbeziers/sec [50% alpha] Text 176.47 11.04 Kchars/sec OpenGL Graphics Test 85.28 Spinning Squares 85.28 108.19 frames/sec User Interface Test 206.77 Elements 206.77 948.95 refresh/sec Disk Test 45.26 Sequential 61.36 Uncached Write 73.14 44.91 MB/sec [4K blocks] Uncached Write 59.70 33.78 MB/sec [256K blocks] Uncached Read 43.29 12.67 MB/sec [4K blocks] Uncached Read 85.74 43.09 MB/sec [256K blocks] Random 35.85 Uncached Write 13.65 1.44 MB/sec [4K blocks] Uncached Write 81.31 26.03 MB/sec [256K blocks] Uncached Read 64.46 0.46 MB/sec [4K blocks] Uncached Read 95.46 17.71 MB/sec [256K blocks] 64 bit: Results 118.74 System Info Xbench Version 1.3 System Version 10.6 (10A402a) Physical RAM 2048 MB Model MacBookPro5,5 Drive Type FUJITSU MJA2160BH FFS G1 CPU Test 148.97 GCD Loop 264.54 13.94 Mops/sec Floating Point Basic 130.09 3.09 Gflop/sec vecLib FFT 89.54 2.95 Gflop/sec Floating Point Library 237.28 41.32 Mops/sec Thread Test 316.68 Computation 435.20 8.82 Mops/sec, 4 threads Lock Contention 248.90 10.71 Mlocks/sec, 4 threads Memory Test 190.49 System 236.19 Allocate 428.71 1.57 Malloc/sec Fill 177.48 8629.31 MB/sec Copy 211.20 4362.32 MB/sec Stream 159.61 Copy 154.08 3182.48 MB/sec Scale 150.28 3104.66 MB/sec Add 168.55 3590.37 MB/sec Triad 167.11 3574.88 MB/sec Quartz Graphics Test 168.45 Line 152.35 10.14 Klines/sec [50% alpha] Rectangle 193.47 57.76 Krects/sec [50% alpha] Circle 165.09 13.46 Kcircles/sec [50% alpha] Bezier 177.40 4.47 Kbeziers/sec [50% alpha] Text 159.87 10.00 Kchars/sec OpenGL Graphics Test 85.45 Spinning Squares 85.45 108.40 frames/sec User Interface Test 224.68 Elements 224.68 1.03 Krefresh/sec Disk Test 46.00 Sequential 61.17 Uncached Write 72.57 44.55 MB/sec [4K blocks] Uncached Write 61.01 34.52 MB/sec [256K blocks] Uncached Read 42.79 12.52 MB/sec [4K blocks] Uncached Read 84.39 42.41 MB/sec [256K blocks] Random 36.86 Uncached Write 14.28 1.51 MB/sec [4K blocks] Uncached Write 81.75 26.17 MB/sec [256K blocks] Uncached Read 63.70 0.45 MB/sec [4K blocks] Uncached Read 94.74 17.58 MB/sec [256K blocks] Talk to you later, -Loren Link to comment Share on other sites More sharing options...
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