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Overclocking comments
My build is the following:
Gigabyte GA-EP35-DS3P motherboard
Intel Core 2 Quad Q6600 Kentsfield 2.4Ghz Processor (SLACR, G0 stepping)
OCZ Reaper HPC Edition 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 Memory
Antec P182 Gun Metal Black ATX Mid Tower Computer Case
Thermalright Ultra-120 eXtreme CPU Cooler
5 x Scythe S-FLEX SFF21F 120mm Case Fans
CORSAIR CMPSU-620HX ATX12V v2.2 and EPS12V 2.91 620W Power Supply (modular)
Western Digital Raptor WD1500ADFD 150GB 10,000 RPM SATA 1.5Gb/s Hard Drive
LITE-ON 20X DVD?R DVD Burner with LightScribe Black SATA Model LH-20A1L-06
Finally, the other shoe dropped, and overclocking went from mysterious to
obvious. I'm running 3.00 Ghz cpu, 1066 Mhz 5-5-5-15 memory, all at stock
voltages except the "stock" increase to 2.1V for the memory, which can take
2.2V without voiding the lifetime warranty.
My core temps stay below 60C, and that's with the cpu cooler fan on
motherboard speed control; one could attach two fans in a push-pull
configuration running full tilt, to get further on air.
I view this as a very conservative build, what one might do if one "isn't"
overclocking (!). I plan to leave this on 24/7, often at full load doing math
computations. I had to start raising the CPU voltage slightly at 3.30 Ghz, and
I gave up as the core temps crossed 60C, with no end in sight. People have
easily reached 3.6 Ghz on air with rigs like this.
Selecting parts for this build involved overcoming pet prejudices, such as
"There's Corsair, then there's everyone else" for memory, or "Ooh! Ooh!
Doesn't the copper Ninja look like the best heat sink ever? Object lust!"
Saying this on any forum seems to be bait to get people to chime in on their
pet prejudices. I'm only willing to believe tough comparative reviews, and
there are many out there. Before overclocking, this rig ran cooler at full
load than my previous Q6600 rig runs at idle. That's how one gets a margin for
overclocking.
This passes stress tests that are harder than 24 hours of mprime (Prime95 for
Linux). My favorite is to run 400 builds from source of the GHC Haskell
compiler, 4 or 8 builds at a time, which takes days. A friend tried this with
a $10K workstation he had built for him (8 cores, 64 GB ram), and apparently
the builder had guessed the power supply needs seat-of-the-pants. My stress
test blew his power supply, literally curling smoke into the room. So this is
a "real world" stress test. My rig passes this test.
The short course for conservatively overclocking this board:
=> Fix the PCI Express Freq at stock, 100 Mhz
=> Increment the CPU Host Freq to raise the CPU clock 0.1 Ghz at a time
=> Find a Sys Mem divider that keeps the Mem Freq <= 800 Mhz
... and nudge one's way up, stress-testing the setup until voltage increases
are needed for stability, then back off. Now relax the memory timings, and
separately see how high one can push the memory clock, by changing the memory
mulitplier.
The overriding principle is to disable any automatic help that the BIOS
offers. Nothing I tried with its help worked, but manually overclocking this
board is a piece of cake, even for a newbie like me.
Note that I'm "forced" to manually control all voltages, because the automatic
setting won't give my memory the needed boost. This is ok, increasing voltages
is a slippery slope, where components get hotter, needing more volts, which
makes them hotter... For conservative overclocking, see what you can do with
stock voltages.
Here are my BIOS changes:
CPU Frequency (Ghz) 3.00
CPU Host Clock Control Manual
CPU Host Frequency (Mhz) 333
PCI Express Frequency (Mhz) 100
Performance Enhance Standard
System Memory Multiplier (SPD) 3.2
Memory Frequency (Mhz) 1066
DRAM Timing Selectable (SPD) Manual
CAS Latency Time 5
DRAM RAS# to CAS# Delay 5
DRAM RAS# Precharge 5
Precharge delay (tRAS) 15
System Voltage Control Manual
DDR2 Overvoltage Control (+V) 0.3
CPU Voltage Control Normal
Normal CPU Vcore (V) 1.275
My build is the following:
Gigabyte GA-EP35-DS3P motherboard
Intel Core 2 Quad Q6600 Kentsfield 2.4Ghz Processor (SLACR, G0 stepping)
OCZ Reaper HPC Edition 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 Memory
Antec P182 Gun Metal Black ATX Mid Tower Computer Case
Thermalright Ultra-120 eXtreme CPU Cooler
5 x Scythe S-FLEX SFF21F 120mm Case Fans
CORSAIR CMPSU-620HX ATX12V v2.2 and EPS12V 2.91 620W Power Supply (modular)
Western Digital Raptor WD1500ADFD 150GB 10,000 RPM SATA 1.5Gb/s Hard Drive
LITE-ON 20X DVD?R DVD Burner with LightScribe Black SATA Model LH-20A1L-06
Finally, the other shoe dropped, and overclocking went from mysterious to
obvious. I'm running 3.00 Ghz cpu, 1066 Mhz 5-5-5-15 memory, all at stock
voltages except the "stock" increase to 2.1V for the memory, which can take
2.2V without voiding the lifetime warranty.
My core temps stay below 60C, and that's with the cpu cooler fan on
motherboard speed control; one could attach two fans in a push-pull
configuration running full tilt, to get further on air.
I view this as a very conservative build, what one might do if one "isn't"
overclocking (!). I plan to leave this on 24/7, often at full load doing math
computations. I had to start raising the CPU voltage slightly at 3.30 Ghz, and
I gave up as the core temps crossed 60C, with no end in sight. People have
easily reached 3.6 Ghz on air with rigs like this.
Selecting parts for this build involved overcoming pet prejudices, such as
"There's Corsair, then there's everyone else" for memory, or "Ooh! Ooh!
Doesn't the copper Ninja look like the best heat sink ever? Object lust!"
Saying this on any forum seems to be bait to get people to chime in on their
pet prejudices. I'm only willing to believe tough comparative reviews, and
there are many out there. Before overclocking, this rig ran cooler at full
load than my previous Q6600 rig runs at idle. That's how one gets a margin for
overclocking.
This passes stress tests that are harder than 24 hours of mprime (Prime95 for
Linux). My favorite is to run 400 builds from source of the GHC Haskell
compiler, 4 or 8 builds at a time, which takes days. A friend tried this with
a $10K workstation he had built for him (8 cores, 64 GB ram), and apparently
the builder had guessed the power supply needs seat-of-the-pants. My stress
test blew his power supply, literally curling smoke into the room. So this is
a "real world" stress test. My rig passes this test.
The short course for conservatively overclocking this board:
=> Fix the PCI Express Freq at stock, 100 Mhz
=> Increment the CPU Host Freq to raise the CPU clock 0.1 Ghz at a time
=> Find a Sys Mem divider that keeps the Mem Freq <= 800 Mhz
... and nudge one's way up, stress-testing the setup until voltage increases
are needed for stability, then back off. Now relax the memory timings, and
separately see how high one can push the memory clock, by changing the memory
mulitplier.
The overriding principle is to disable any automatic help that the BIOS
offers. Nothing I tried with its help worked, but manually overclocking this
board is a piece of cake, even for a newbie like me.
Note that I'm "forced" to manually control all voltages, because the automatic
setting won't give my memory the needed boost. This is ok, increasing voltages
is a slippery slope, where components get hotter, needing more volts, which
makes them hotter... For conservative overclocking, see what you can do with
stock voltages.
Here are my BIOS changes:
CPU Frequency (Ghz) 3.00
CPU Host Clock Control Manual
CPU Host Frequency (Mhz) 333
PCI Express Frequency (Mhz) 100
Performance Enhance Standard
System Memory Multiplier (SPD) 3.2
Memory Frequency (Mhz) 1066
DRAM Timing Selectable (SPD) Manual
CAS Latency Time 5
DRAM RAS# to CAS# Delay 5
DRAM RAS# Precharge 5
Precharge delay (tRAS) 15
System Voltage Control Manual
DDR2 Overvoltage Control (+V) 0.3
CPU Voltage Control Normal
Normal CPU Vcore (V) 1.275
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