Hi, anyone can tell me what you gain by overclocking a dual 1.42 @ 1.5, and @1.67...?
Thanks.
Exactly what you would expect mathematically. It's linear.
The difference between my 1.42 and 1.5 with no other changes to system:
1.42:
Results 66.64
System Info
Xbench Version 1.3
System Version 10.5.8 (9L31a)
Physical RAM 2048 MB
Model PowerMac3,6
Processor PowerPC G4x2 @ 1.42 GHz
Version 7455 (Apollo) v3.3
L1 Cache 32K (instruction), 32K (data)
L2 Cache 256K @ 1.42 GHz
L3 Cache 2048K @ 237 MHz
Bus Frequency 167 MHz
Video Card ATY,R350
Drive Type ST3500418AS ST3500418AS
CPU Test 76.67
GCD Loop 135.60 7.15 Mops/sec
Floating Point Basic 49.63 1.18 Gflop/sec
AltiVec Basic 279.53 11.14 Gflop/sec
vecLib FFT 83.18 2.74 Gflop/sec
Floating Point Library 45.27 7.88 Mops/sec
Thread Test 74.53
Computation 110.92 2.25 Mops/sec, 4 threads
Lock Contention 56.12 2.41 Mlocks/sec, 4 threads
Memory Test 49.94
System 57.88
Allocate 219.72 806.90 Kalloc/sec
Fill 56.66 2754.73 MB/sec
Copy 33.75 697.10 MB/sec
Stream 43.92
Copy 46.78 966.27 MB/sec [altivec]
Scale 47.49 981.05 MB/sec [altivec]
Add 43.27 921.66 MB/sec [altivec]
Triad 39.17 837.89 MB/sec [altivec]
Quartz Graphics Test 86.61
Line 73.60 4.90 Klines/sec [50% alpha]
Rectangle 78.24 23.36 Krects/sec [50% alpha]
Circle 70.59 5.75 Kcircles/sec [50% alpha]
Bezier 81.44 2.05 Kbeziers/sec [50% alpha]
Text 203.25 12.71 Kchars/sec
OpenGL Graphics Test 76.31
Spinning Squares 76.31 96.81 frames/sec
User Interface Test 51.33
Elements 51.33 235.59 refresh/sec
Disk Test 69.28
Sequential 128.44
Uncached Write 144.58 88.77 MB/sec [4K blocks]
Uncached Write 142.07 80.39 MB/sec [256K blocks]
Uncached Read 91.10 26.66 MB/sec [4K blocks]
Uncached Read 161.03 80.93 MB/sec [256K blocks]
Random 47.43
Uncached Write 15.70 1.66 MB/sec [4K blocks]
Uncached Write 222.19 71.13 MB/sec [256K blocks]
Uncached Read 101.71 0.72 MB/sec [4K blocks]
Uncached Read 158.33 29.38 MB/sec [256K blocks]
1.5:
Results 71.72
System Info
Xbench Version 1.3
System Version 10.5.8 (9L31a)
Physical RAM 2048 MB
Model PowerMac3,6
Processor PowerPC G4x2 @ 1.50 GHz
Version 7455 (Apollo) v3.3
L1 Cache 32K (instruction), 32K (data)
L2 Cache 256K @ 1.50 GHz
L3 Cache 2048K @ 250 MHz
Bus Frequency 167 MHz
Video Card ATY,R350
Drive Type ST3500418AS ST3500418AS
CPU Test 81.35
GCD Loop 143.74 7.58 Mops/sec
Floating Point Basic 52.66 1.25 Gflop/sec
AltiVec Basic 297.59 11.86 Gflop/sec
vecLib FFT 88.32 2.91 Gflop/sec
Floating Point Library 47.99 8.36 Mops/sec
Thread Test 88.62
Computation 121.92 2.47 Mops/sec, 4 threads
Lock Contention 69.61 2.99 Mlocks/sec, 4 threads
Memory Test 51.83
System 64.44
Allocate 277.47 1.02 Malloc/sec
Fill 64.32 3127.43 MB/sec
Copy 36.49 753.63 MB/sec
Stream 43.35
Copy 45.42 938.19 MB/sec [altivec]
Scale 47.27 976.53 MB/sec [altivec]
Add 41.99 894.47 MB/sec [altivec]
Triad 39.54 845.87 MB/sec [altivec]
Quartz Graphics Test 93.12
Line 75.04 5.00 Klines/sec [50% alpha]
Rectangle 83.83 25.03 Krects/sec [50% alpha]
Circle 80.02 6.52 Kcircles/sec [50% alpha]
Bezier 88.64 2.24 Kbeziers/sec [50% alpha]
Text 214.66 13.43 Kchars/sec
OpenGL Graphics Test 80.02
Spinning Squares 80.02 101.51 frames/sec
User Interface Test 58.33
Elements 58.33 267.70 refresh/sec
Disk Test 69.69
Sequential 128.73
Uncached Write 145.26 89.19 MB/sec [4K blocks]
Uncached Write 142.69 80.74 MB/sec [256K blocks]
Uncached Read 90.53 26.49 MB/sec [4K blocks]
Uncached Read 163.01 81.93 MB/sec [256K blocks]
Random 47.77
Uncached Write 15.77 1.67 MB/sec [4K blocks]
Uncached Write 228.73 73.23 MB/sec [256K blocks]
Uncached Read 103.94 0.74 MB/sec [4K blocks]
Uncached Read 157.73 29.27 MB/sec [256K blocks]
1.58 was also stable for mine, but the temperature jumped a little above my comfort level so I dropped it back down (my comfort level for temperature is much below manufacturer's specs).
Of course, not all 1.42's are going to be the same. As long as you're comfortable with your soldering skills, though, it doesn't hurt try for something higher and then drop it back down if it doesn't work out. I think 1.5 is pretty much a given for any 1.42. My impression based on what I've read and done (I can't quantify this in any way. People are probably more likely to post about their victories than their failures, so I'm basically pulling this out of my you know what) is that 1.5 is a given, 1.58 works more often than not, and the odds are against you at 1.67 (people seem to have more success with water cooling). If I'm not mistaken, though, at least one user here has gotten 1.67 without water cooling. Maybe 666Sheep?
I would strongly urge you, Nova77, to consider using CHUD if this is the next step for your MDD. It might make the difference between something you're comfortable with and something that you're not. The cooler they run, the longer they will last.