Q9550 voltage question

C

Calefaction

Limp Gawd
Joined
Sep 1, 2004
Messages
335
I know everyone here has moved on to Core i5/i7, but I'm still a "dinosaur" with an LGA775 Q9550.

I am going to overclock it to ~3.0ghz, but I am wondering what the safe voltages are. It will be air cooled, but not with the stock cooler. My case has great airflow, so I am not really worried about heat at 3.0ghz, I just want to make sure I don't overvolt the thing. I know it won't even boot at 366mhz bus speed on my P45 without taking the volts above stock (I know, I've tried), so I know a voltage tweak is my next step, I am always just very leery about voltage changes to CPU's.

I know, it's not a very aggressive overclock, but it works for my purposes, and I'm big in to keeping my hardware in decent shape for a while, I don't like to burn stuff out with super aggressive overclocks.
 
What's your VID? I'm pretty sure most Q9550s can hit 3.00ghz at VID voltage. My extremely high 1.275VID chip hits 3.00 at 1.2 vcore.

General rules of thumb are to stay below 1.4 vcore and vtt. You definitely do not need either of those that high for a low overclock. Don't forget about the NB voltage too.
 
Should be very easy to hit 3.0GHz without modification of the voltage. I am running mine ~3.1 GHz at 1.15V. It most likely could go much higher but it must be 100% stable 24/7 so I take it a little at a time.
 
Hmm, strange. I tried to do it by simply jumping the bus speed up to 366 and dropping the multiplier to 8x, and the system wouldn't boot. I have a Gigabyte GA-EP45-UD3P, and when it won't accept an overlock, it simply reboots a couple of times and goes back to the last known good configuration, and that's what it's doing. I figured the only possibility was that it wasn't getting enough voltage to go to that bus speed.

I didn't touch the NB volts though. Would the NB volts stop it from booting up if it was undervolted?

I haven't done any serious overclocking since I had my Opteron 165, so I am a little out of the loop with overclocking Core 2 CPU's.
 
I’m not an OC expert but common, only 3.0 GHz?! and with that awesome board ?!

not the best OC settings out their but those are what I’ve been using for about a year now:

Code: 
******Motherboard Intelligent Tweaker (M.I.T.)******
 
Robust Graphics Booster.........................[ Auto     ]
CPU Clock Ratio.................................[ 8        ]
Fine CPU Clock Ratio............................[ + 0.5    ]
CPU Frequency 3.6GHz............................[ 425 x 8.5  ]
 
******Clock Chip Control******
 
CPU Host Clock Control..........................[ Enabled  ]
CPU Host Frequency (Mhz)........................[ 425      ]
PCI Express Frequency (Mhz).....................[ 100      ]
C.I.A 2 [Disabled] 
 
******Advanced Clock Control******

CPU Clock Drive.................................[ 800mv]
PCI Express Clock Drive.........................[ 900mv]
CPU Clock Skew..................................[ 0ps]
MCH Clock Skew..................................[ 0ps]
 
******DRAM Performance Control******
 
Performance Enhance.............................[Standard]
Extreme Memory Profile (XMP)....................[ Auto   ]
(G) MCH Frequency Latch.........................[ 333    ]
System Memory Multiplier........................[ 2.40B  ]
Memory Frequency   ..............1066.............1020
DRAM Timing Selectable..........................[ Manual ]
 
CAS Latency Time...............[ 5    ].........[ 5     ]
tRCD...........................[ 5    ].........[ 5     ]
tRP............................[ 5    ].........[ 5     ]
tRAS...........................[ 15   ].........[ 15    ]
 
******Advanced Timing Control******
 
tRRD...........................[ 4   ]..........[ Auto     ]
tWTR...........................[ 4   ]..........[ Auto     ]
tWR............................[ 6   ]..........[ Auto     ]
tRFC...........................[ 72   ].........[ 54       ]
tRTP...........................[ 4   ]..........[ Auto     ]
Command Rate (cmd).............[ 0   ]..........[ 2        ]
 
******Channel A Timing Settings******     
 
Static tRead Value        [ 8 ] ................[ 8        ]
tRD Phase0 Adjustment     [ 0 ] ................[ Auto     ]
tRD Phase1 Adjustment     [ 0 ] ................[ Auto     ]
tRD Phase2 Adjustment     [ 0 ] ................[ Auto     ]
tRD Phase3 Adjustment     [ 0 ] ................[ Auto     ]
 
tRD 2rd (Differnt Rank)   [ 8 ] ................[ Auto     ]
tWR 2wr (Differnt Rank)   [ 8 ] ................[ Auto     ]
tWR 2rd (Differnt Rank)   [ 7 ] ................[ Auto     ]
tRD 2wr (Same/Difft Rank) [ 9 ] ................[ Auto     ]
 
Dimm 1 Clock Skew Control.......................[ Auto     ]
Dimm 2 Clock Skew Control.......................[ Auto     ]
DDR Write Training..............................[ Auto     ]
 
******Channel A Driving Settings****** 
 
Drive Strength Profile..........................[ Auto     ]
Data Driving Pull Up Level......................[ Auto     ]
cmd Driving Pull Up Level.......................[ Auto     ]
ctrl Driving Pull Up Level......................[ Auto     ]
clk Driving Pull Up Level.......................[ Auto     ]
 
Data Driving Pull Down Level....................[ Auto     ]
cmd Driving Pull Down Level.....................[ Auto     ]
ctrl Driving Pull Down Level....................[ Auto     ]
clk Driving Pull Down Level.....................[ Auto     ]
 
******Channel B Timing Settings******     
 
Static tRead Value        [ 8 ] ................[ 8        ]
tRD Phase0 Adjustment     [ 0 ] ................[ Auto     ]
tRD Phase1 Adjustment     [ 0 ] ................[ Auto     ]
tRD Phase2 Adjustment     [ 0 ] ................[ Auto     ]
tRD Phase3 Adjustment     [ 0 ] ................[ Auto     ]
 
tRD 2rd (Differnt Rank)   [ 8 ] ................[ Auto     ]
tWR 2wr (Differnt Rank)   [ 8 ] ................[ Auto     ]
tWR 2rd (Differnt Rank)   [ 7 ] ................[ Auto     ]
tRD 2wr (Same/Difft Rank) [ 9 ] ................[ Auto     ]
 
Dimm 1 Clock Skew Control.......................[ Auto     ]
Dimm 2 Clock Skew Control.......................[ Auto     ]
DDR Write Training..............................[ Auto     ]
 
******Channel B Driving Settings****** 
 
Drive Strength Profile..........................[ Auto     ]
Data Driving Pull Up Level......................[ Auto     ]
cmd Driving Pull Up Level.......................[ Auto     ]
ctrl Driving Pull Up Level......................[ Auto     ]
clk Driving Pull Up Level.......................[ Auto     ]
 
Data Driving Pull Down Level....................[ Auto     ]
cmd Driving Pull Down Level.....................[ Auto     ]
ctrl Driving Pull Down Level....................[ Auto     ]
clk Driving Pull Down Level.....................[ Auto     ]
 
******Motherboard Voltage Control******
 
Load-Line Calibration...........................[ Enabled  ]
CPU Vcore         [ 1.25    ]...................[ 1.2250V  ]
CPU Termination   [ 1.20    ]...................[ 1.20     ]
CPU PLL           [ 1.50    ]...................[ 1.50     ]
CPU Reference     [ 0.760   ]...................[ Auto     ]
 
MCH Core          [ 1.100   ]...................[ 1.240   ]
MCH Reference     [ 0.760   ]...................[ 0.800   ]
MCH/DRAM Refernce [ 0.900   ]...................[ 0.960   ]
ICH I/O           [ 1.500   ]...................[ 1.500   ]
ICH Core          [ 1.100   ]...................[ 1.100   ]

DRAM Voltage      [1.8]...................[1.920] 
DRAM Termination  [0.9]...................[0.960]
Channel A Ref     [0.9]...................[0.960]
Channel B Ref     [0.9]...................[0.960]

*****************Advanced BIOS Features********* 


Limit CPUID Max to 3 ................. [disable] 
No-Execute memory Protect ............ [disable]
CPU Enhance Halt (CIE) ............... [disable] 
C2/C2E State Support ................. [disable] 
C4/C4E State Support ................. [disable] 
CPU Thermal Monitor................... [disable] 
CPU EIST Function..................... [disable]
Virtualization Technology ............ [disable]

you have 1066 PC-8500 RAM’s (like mine) and they should run at 1020 (underclocked) if you use the same memory settings, but you can use different memory multiplier to achieve higher speed (1200 if I remember correctly), just remember to flash your bios to the latest version because I heard they solved some issues with the memory settings lately, and do notice that I did that 3.6 on stock voltage.

Calefaction said:
it simply reboots a couple of times
Click to expand...

GIGABYTE DualBIOS, it's loading the backup bios.
 
Last edited:
Okay, not to thread necro this, but I wanted to come back and give a little bit of a post mortem, now that I have my memory RMA'ed and have the system up and running stable.

First off, big thanks to firas for his BIOS settings, they were a great starting point for the Gigabyte GA-EP45-UD3P. My final overclock is definitely somewhat tame (3.2ghz), but it's stable, which was my number one priority.

I was able to get the system to boot cleanly at 3.4ghz with the memory running at 1066, but I got tons of boot stability issues. The system itself would run fine, and would even pass through memtest86+ and various runs of Prime95 and Orthos, but I would get strange issues on boot. Sometimes the system wouldn't post, other times it would hang when attempting to detect the amount of DRAM in the system, other times it would hang when detecting the HDD's. Other times it would boot perfectly fine. This all made me very nervous, so I backed the OC down to it's current 3.2ghz. The memory is running at 878mhz, though I plan to tweak that some more at some point.

Voltages in my case are stock for the CPU, and only slightly elevated for the MCH and the DRAM itself. I am running:

MCH Core: 1.200
MCH Reference 0.800
MCH/DRAM Refence: 0.920

DRAM: 1.900 (this will go up when I attempt to make the memory run closer to it's 1066 rating)
DRAM Termination: 0.940
Channel A Ref: 0.940
Channel B Ref: 0,940

All other voltages are stock.

One gotcha I did have, that may help another aspiring overclocker: I had to hand set the timings to the rated 5-5-5-15. For some reason, when I attempted to run the memory at speeds above 800mhz, the board would SPD detect 5-8-8-18 (as reported by CPU-Z), which is not what I wanted. Manually setting 5-5-5-15 worked, and has been completely stable.

Anyways, I just wanted to come back an give an update. If you have a Q9550 and are wondering if you should overclock it, I recommend it. It was relatively painless, and so far my modest overclock hasn't raised my temperatures by any noticeable amount. My idle temp is still the same, and it never spikes higher under load than it did at stock.
 
3.2ghz is a wimpy OC for this chip. you should really try higher with the same vcore. i had my old one up to 4.3ghz stable, but this was on an asus board and required lots of tuning to get this high. not sure about the gigabyte board, but if you have skews and gtl options in the bios, if you tune it at a sweet spot, you'll be able to raise the fsb while lowering vcore. these settings don't much that much of a difference for dual cores, but for quads, it'll determine if you're stable or not at high OC's.
 
I am aware the OC is "wimpy". Thankfully for me, I am more worried about rock solid system stability than winning an overclock e-Peen contest.
 
I don't get why you aren't running 1:1 on the RAM. E.g. if you were using a 1:1 RAM divider and the 8.5x multiplier, than you easily get 3.6Ghz at only 423Mhz. Because both the P45 chipset and your RAM have plenty of headroom at that FSB, your only limitation is vcore required for your chip.
 
Mostly because when I got close to 1:1, the system started to display nasty boot issues. It would RUN stable, but I don't like a machine that decides from time to time it won't turn on. Several times it triggered the DualBIOS stuff, despite running decently stable with the same settings. This is with the latest BIOS for the board.

This could be a case that I don't have a stepping E0 Q9550, not sure. Frankly I'm not willing to play the RMA game until I get one either.
 
That kinda sucks, since 1:1 would definitely prevent the RAM from limiting your OC. As you mentioned in your post, after 533Mhz, you experienced instability - which is expected, given your RAM is rated for 531Mhz. Oops, and now I just noticed you have 8GB (not 4). So safe to guess you four 2GB sticks - you probably need to bump your NB more than normal to accomodate that.
 
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