Been playing with y-cruncher for a bit to stress test. Nice to spot memory errors when messing with timings.
Using an AMD 940 @3.5ghz 14x250mhz, 8gb ram. For the advanced swap runs was using 4 completely different drives, just what I had around. 150 WD VelociRaptor , 34 GB WD Raptor, 1TB WD, 500GB WD. Wound up giving me a bit over 200MB/s read/writing.

Code:
Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,499,968,327 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        10,000,000,000
Hexadecimal Digits:    8,304,820,238
Threading Mode:        4 threads
Computation Mode:      Advanced Swap
Swap Disks:            4
Working Memory:        7.03 GB

Start Time:            Sun May 30 03:45:01 2010
End Time:              Sun May 30 09:25:45 2010

Computation Time:      19,213.444 seconds
Total Time:            20,444.781 seconds

CPU Utilization:           212.99 %
Multi-core Efficiency:     53.24 %

Last Digits:
9763261541 1423749758 2083180752 2573977719 9605119144  :  9,999,999,950
9403994581 8580686529 2375008092 3106244131 4758821220  :  10,000,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   afbb8decc6372e5e02c4830fe70bf4be45f24dca0e6d814b1dcb7831b80f25a7



Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,499,971,970 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        5,000,000,000
Hexadecimal Digits:    4,152,410,119
Threading Mode:        4 threads
Computation Mode:      Advanced Swap
Swap Disks:            4
Working Memory:        6.89 GB

Start Time:            Tue Jan 06 00:46:02 2009
End Time:              Tue Jan 06 03:21:46 2009

Computation Time:      8,656.553 seconds
Total Time:            9,344.830 seconds

CPU Utilization:           207.96 %
Multi-core Efficiency:     51.99 %

Last Digits:
4384678622 1397184596 0181195416 0748430457 5386741865  :  4,999,999,950
0914971996 1298184401 9216126684 9425834935 5440797257  :  5,000,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   3e90e3bd4bda69b81b6bba5e8607b4645e3e4d386de0e1e70209677b8adeadb1



Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,499,964,882 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        2,500,000,000
Hexadecimal Digits:    2,076,205,060
Threading Mode:        4 threads
Computation Mode:      Basic Swap
Swap Disks:            1
Working Memory:        5.09 GB

Start Time:            Sun May 30 13:51:33 2010
End Time:              Sun May 30 14:46:07 2010

Computation Time:      3,064.283 seconds
Total Time:            3,274.682 seconds

CPU Utilization:           252.08 %
Multi-core Efficiency:     63.02 %

Last Digits:
0917027898 3554136437 7123165188 3528593128 0032489094  :  2,499,999,950
9228502005 4677489552 2459688725 5242233502 7255998083  :  2,500,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   6d96b2b94cefff2e1c5d4262bea9ea1781508808f286eb8e16b268f48db790d0



Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,500,033,606 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        1,000,000,000
Hexadecimal Digits:    Disabled
Threading Mode:        4 threads
Computation Mode:      Ram Only
Swap Disks:            0
Working Memory:        4.75 GB

Start Time:            Mon Jan 05 22:48:11 2009
End Time:              Mon Jan 05 23:00:23 2009

Computation Time:      698.078 seconds
Total Time:            732.356 seconds

CPU Utilization:           388.09 %
Multi-core Efficiency:     97.02 %

Last Digits:
6434543524 2766553567 4357021939 6394581990 5483278746  :  999,999,950
7139868209 3196353628 2046127557 1517139511 5275045519  :  1,000,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   8aa91c4c41b343c601786c9d3e1daff73d41adcccde3af4e112263b548cf620a



Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,499,962,659 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        500,000,000
Hexadecimal Digits:    Disabled
Threading Mode:        4 threads
Computation Mode:      Ram Only
Swap Disks:            0
Working Memory:        2.42 GB

Start Time:            Mon Jan 05 23:03:11 2009
End Time:              Mon Jan 05 23:08:44 2009

Computation Time:      315.981 seconds
Total Time:            333.237 seconds

CPU Utilization:           379.80 %
Multi-core Efficiency:     94.95 %

Last Digits:
3896531789 0364496761 5664275325 5483742003 7847987772  :  499,999,950
5002477883 0364214864 5906800532 7052368734 3293261427  :  500,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   ce7f605a99f54b62064bd9e20452d0334d80ff539a58a59b1623b0a7eeb2b6cd



Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,499,970,806 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        250,000,000
Hexadecimal Digits:    Disabled
Threading Mode:        4 threads
Computation Mode:      Ram Only
Swap Disks:            0
Working Memory:        1.25 GB

Start Time:            Mon Jan 05 23:11:59 2009
End Time:              Mon Jan 05 23:14:27 2009

Computation Time:      138.842 seconds
Total Time:            147.274 seconds

CPU Utilization:           386.50 %
Multi-core Efficiency:     96.62 %

Last Digits:
3673748634 2742427296 0219667627 3141599893 4569474921  :  249,999,950
9958866734 1705167068 8515785208 0067520395 3452027780  :  250,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   c67582ba838a1805035d66a9aa0012a5b229242cc2f0142706ce4ca19982209a



Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,499,962,238 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        100,000,000
Hexadecimal Digits:    Disabled
Threading Mode:        4 threads
Computation Mode:      Ram Only
Swap Disks:            0
Working Memory:        536 MB

Start Time:            Mon Jan 05 23:27:29 2009
End Time:              Mon Jan 05 23:28:21 2009

Computation Time:      48.551 seconds
Total Time:            52.071 seconds

CPU Utilization:           379.88 %
Multi-core Efficiency:     94.97 %

Last Digits:
9948682556 3967530560 3352869667 7734610718 4471868529  :  99,999,950
7572203175 2074898161 1683139375 1497058112 0187751592  :  100,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   6aadf6c6c06bcd62113787fa59d8a1a9a24150dd43ca557d1677b4b4ff6a46b1



Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,499,961,443 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        50,000,000
Hexadecimal Digits:    Disabled
Threading Mode:        4 threads
Computation Mode:      Ram Only
Swap Disks:            0
Working Memory:        317 MB

Start Time:            Mon Jan 05 23:30:54 2009
End Time:              Mon Jan 05 23:31:18 2009

Computation Time:      21.789 seconds
Total Time:            23.675 seconds

CPU Utilization:           378.19 %
Multi-core Efficiency:     94.54 %

Last Digits:
4127897300 0153683630 8346732220 0943329365 1632962502  :  49,999,950
5130045796 0464561703 2424263071 4554183801 7945652654  :  50,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   99b5ff37390549200f27bb917a4efa88987414e8cf0d2545112712f971118986



Validation Version:    1.1

Program:               y-cruncher - Gamma to the eXtReMe!!!     ( www.numberworld.org )
                       Copyright 2008-2010 Alexander J. Yee    ( a-yee@northwestern.edu )


User:                  CRFX


Processor(s):          AMD Phenom(tm) II X4 940 Processor
Logical Cores:         4
Physical Memory:       8,588,873,728 bytes  ( 8.00 GB )
CPU Frequency:         3,499,974,798 Hz

Program Version:       0.5.3 Build 9134b (fix 2) (x64 SSE3 - Windows ~ Kasumi)
Constant:              Pi
Algorithm:             Chudnovsky Formula
Decimal Digits:        25,000,000
Hexadecimal Digits:    Disabled
Threading Mode:        4 threads
Computation Mode:      Ram Only
Swap Disks:            0
Working Memory:        207 MB

Start Time:            Mon Jan 05 23:30:00 2009
End Time:              Mon Jan 05 23:30:11 2009

Computation Time:      9.945 seconds
Total Time:            11.036 seconds

CPU Utilization:           368.58 %
Multi-core Efficiency:     92.14 %

Last Digits:
3803750790 9491563108 2381689226 7224175329 0045253446  :  24,999,950
0786411592 4597806944 2455112852 2554677483 6191884322  :  25,000,000

Timer Sanity Check:        Passed
Frequency Sanity Check:    Passed
ECC Recovered Errors:      0

----

Checksum:   9a4bb1bb0b6858fa01b70a9a0ba412b09c8f9011565814aa1db8631060a5e5c7