Odd divisor correct and what it does.

[eva2000]

A64Info math is based on Oscar's table. I'm assuming that 180 is actualy 183.00MHz. Same goes for 140 -> 143.00MHz. Only 11 multi is problematic with 180 divider since it is on the edge (12 if you assume 183.333... or 12.02, if you assume 183.00, thus making it 13). I have proposed test to solve this dilemma but no one responded:

http://www.xtremesystems.org/forums/...8&postcount=57

This post also convinced me that divider is 13:

http://xtremesystems.org/forums/show...6&postcount=40

My firiend managed to measure bandwidths, but it is only one case:

http://www.xtremesystems.org/forums/...9&postcount=59

It is importain to maintain the same memory timings in both tests. Unfortunately, I do not have CPU with 11 multi to test it.

Ran 32M and definitely the ram is running 251mhz at 11x274HTT with 180 divider the time of 23min 54s is spot on for the ram it seems.



Settings used

FSB Bus Frequency: 274
LDT/FSB Frequency Ratio: 4x
CPU/FSB Frequency Ratio: 11x
RD580 HT PLL Speed: High
HT Bus NMOS Drive Strength: 5
HT Bus PMOS Drive Strength: 5
HT Bus Receiver Impendence: 5
CPU HT Bus Drive Strength: Strong
K8 Cool & Quiet Support: Disabled

CPU VID Control: 1.55v
CPU VID Special Control: AUTO
DRAM Voltage Control: 3.4v
SB PCIE Voltage: 1.8v
NB Analogue Voltage: 1.34v
LDT Bus Voltage: 1.34v
NB Core Voltage: 1.34v

DRAM Frequency Set: 180
CPC: Enabled
CAS (tCL): 2
tRCP: 2
tRAS: 5
tRP: 2
tRC: 7
tRFC: 14
tRRD: 2
tRW: 2
tRTW: 1
tWTR: 2
tREF: 4708
Bank Interleaved: Enabled
Errata 94: Disabled
Errata 123: AUTO
Odd Divisor Correct: Disabled

DQS Skew Control: AUTO
DQS Skew Value: N/A
DRAM Drive Strength: 3 (weak)
DRAM Data Drive Strength: 2 (-33%)
DIMM 1/2 Clock Timing Skew: AUTO
DIMM 3/4 Clock Timing Skew: 150ps delay
Max Async Latency: 7ns (tried 6ns but there was a long delay before booting system)
Read Preamble Time: 5ns
IdleCycle Limit: 16clks
Dynamic Counter: Enabled
R/W Queue Bypass: 16x
Bypass Max: 7x
Burst Length: 4

More tests to confirm ram is at 251mhz 2-2-2-5

Everest Home
Read = 7,191 MB/s
Write = 3,300 MB/s
Latency = 36.1 ns

Sandra 2005 Lite SR3
Buffered = 7,508 / 7,445
Unbuffered = 3,574 / 3,777


vs

10x300HTT = 3000mhz
@250mhz 2-2-2-0 7-12-0211 at 3.44v

Memtest86+ v1.65 bandwidth = 3006MB/s

FSB Bus Frequency: 300
LDT/FSB Frequency Ratio: 4x (tried 5x but system didn't boot even with NMOS/PMOS drive strength @31 so dropped it to 4x)
CPU/FSB Frequency Ratio: 10x
RD580 HT PLL Speed: High
HT Bus NMOS Drive Strength: 5
HT Bus PMOS Drive Strength: 5
HT Bus Receiver Impendence: 5
CPU HT Bus Drive Strength: Strong
K8 Cool & Quiet Support: Disabled

CPU VID Control: 1.5v (set higher due to low vcore + high vdimm issue)
CPU VID Special Control: AUTO
DRAM Voltage Control: 3.44v
SB PCIE Voltage: 1.8v
NB Analogue Voltage: 1.34v
LDT Bus Voltage: 1.34v
NB Core Voltage: 1.34v

DRAM Frequency Set: 166
CPC: Enabled
CAS (tCL): 2
tRCP: 2
tRAS: 0
tRP: 2
tRC: 7
tRFC: 12
tRRD: 0
tRW: 2
tRTW: 1
tWTR: 1
tREF: 4708
Bank Interleaved: Enabled
Errata 94: Disabled
Errata 123: AUTO
Odd Divisor Correct: Disabled

DQS Skew Control: AUTO
DQS Skew Value: N/A
DRAM Drive Strength: 3 (weak)
DRAM Data Drive Strength: 2 (-33%)
DIMM 1/2 Clock Timing Skew: AUTO
DIMM 3/4 Clock Timing Skew: 150ps delay
Max Async Latency: 8ns
Read Preamble Time: 4.5ns
IdleCycle Limit: 0clks
Dynamic Counter: Enabled
R/W Queue Bypass: 16x
Bypass Max: 7x
Burst Length: 8

Super Pi v1.5 32M


The above 23min 59.297s time managed to beat my DFI NF4 Ultra-D time of 23min 59.641s.



Everest Home:
Read = 7,142 MB/s
Write = 3,361 MB/s
Latency = 36.2 ns

Sandra 2005 Lite SR3
Buffered = 7,486 / 7,419
Unbuffered = 3,717 / 3,847