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Problems with 2 pairs of TWIN2X2048-8500C5


brusyev

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Hello everyone,

I am new to this forum but I know that many of you here are very knowledgeable about overcklocking and most of all about Corsair RAM.

 

I have built my system with the goal of overclocking it someday, and now that I am trying to do so, I am seeing that the system is not so stable, even with slightest overclocking. To begin my OCing I have isolated my motherboard to max out at 340 on reference clock. Currently I am running the following. All AI OC settings are off, SLI memory setting is off, reference clock is 320. Multiplier is 10, CPU voltage is 1.46, and RAM voltage is 2.1V, RAM divider is set at 400 with relaxed timings of 5-5-5-15-2T and HHT is at X3. Now here is the strange thing, If I up my RAM divider to 533 or higher my system becomes completely unstable. I tried adding more voltage to RAM max 2.2V and to the CPU but still no luck. When I run Orthos 2 and prime 95 it errors out when I run the Large in Place FFT’s test. I am trying to figure out if the Corsair RAM could be the bottleneck here or my CPU. The only way I can run my RAM at 800 is when I run my CPU at stock settings and even then if I tighten the timings on the RAM, my system crashes. Am I forgetting to do something here or do I simply have defective RAM or CPU? I ran Memtest86 for 24 hours, under stock settings and it passes fine. I am hoping that someone here can shine some light on this problem. I am waiting eagerly for your responses and will post more information if necessary. Thank you all :):

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You are advised to drop the bandwidth one bin and raise the memory controller voltage +.2v.

 

Please research this thread:

 

http://www.houseofhelp.com/v3/showthread.php?t=64360&highlight=Unpredictable+results+QUAD2X4096+Gigabyte+X38-DS5

 

There is a limitation of the On Motherboard (Intel) memory controller and a population of all four banks at the full speed of a two bank run. This limitation is across the board with both AMD and Intel chipset based boards, DDR, DDR2 and DDR3.

 

Keep in mind that often issues can arise in the longer term even though you have shorter term stability. The issues seldom damage the DRAM. They damage the on motherboard memory controller which has a harder time keeping up with the demands of a four DRAM slot population being run as fast as a two DRAM slot population.

 

When you increase the FSB of the processor (HT) you concurrently raise the DRAM speed. Set the DRAM to 800Mhz and raise the FSB (HT) incrementally, memtest and if you pass check your DRAM speed in CPU-z's memory tab. When you find instability and failure in Memtest, you have found your DRAM maximum. Now drop the DRAM speed to 333Mhz and raise the FSB using CPU-z's memory tab to see where your DRAM speed is. When you reach the previously found instability speed, drop the DRAM speed to 266Mhz and repeat the overclock. When you do this, be certain to set your CPU <--> MCP55 HT Multiplier lower. It should not be higher than 1000Mhz. 5 X 200 (Stock) = 1000Mhz. So, if you set your DRAM to 250Mhz then you get 250 X 4 = 1000Mhz and you are fine. 251+ and set the CPU <--> MCP55 HT multiplier to 3.

 

Start with two sticks of DRAM in Slot 1 and 3. Enter your BIOS and set to these values:

 

Jumperfree Configuration

AI Tuning = Manual
CPU Frequency =  200 
CPU Voltage = Manual = Auto 
DDR Voltage Control = 1.9V
CPU Multiplier =  10X
CPU-->Chipset HT Voltage = 1.2V
Chipset Core Voltage = 1.35V
Chipset Standby Core Voltage = Auto
Chipset PCI-e Voltage = Auto
Chipset VCore Offset Voltage = Disabled 

Memory Configuration

Memory Clock Frequency = Manual
Memclock Value = 800Mhz
TCL = 5
TRCD = 5
TRP = 5
TRAS = 15
1T/2T Memory Timing = 2T

DRAM ECC Enable/Disable = Disable

AMD Cool 'n' Quiet Function =  Disabled (For Overclocking)

Advanced Chipset

CPU <--> MCP55 HT Speed =  5X
CPU <--> MCP55 HT Width = 16 X 16

 

Boot to the Memtest CD and allow for two full passes. If the sticks pass, shut the system down and remove the sticks. Insert the second set and retest. If they pass, then insert one set in Slot 2 and 4 and retest. You have now tested all sticks and all slots at 800Mhz.

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Thanks DerekT,

 

I will go ahead and do what you advised, although I have already tested my RAM at 800 Mhz and it passed. I do have a feeling that my RAM will pass all the tests without a problem, but I will try again. I have never thought that the memory controller on the motherboard could be the bottleneck. Could the memory controller be the cause why I can run my ram @ 800Mhz with loose timings of 5-5-5-12-2T but cannot run it @ 800Mhz with timings of 4-4-4-12-T2 using the stock settings: CPU Reference Clock (FSB) = 200, Multiplier 14X, CPU Voltage = 1.39, RAM Voltage 2.1V. I mean if my reference clock (fsb) is so low 200Mhz and RAM is locked at 800Mhz which is below 1066Mhz my ram is capable of. Thank you for the link to the thread, I will give it a read.

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Thanks DerekT,

 

I will go ahead and do what you advised, although I have already tested my RAM at 800 Mhz and it passed. I do have a feeling that my RAM will pass all the tests without a problem, but I will try again. I have never thought that the memory controller on the motherboard could be the bottleneck. Could the memory controller be the cause why I can run my ram @ 800Mhz with loose timings of 5-5-5-12-2T but cannot run it @ 800Mhz with timings of 4-4-4-12-T2 using the stock settings: CPU Reference Clock (FSB) = 200, Multiplier 14X, CPU Voltage = 1.39, RAM Voltage 2.1V. I mean if my reference clock (fsb) is so low 200Mhz and RAM is locked at 800Mhz which is below 1066Mhz my ram is capable of. Thank you for the link to the thread, I will give it a read.

 

I doubt that that issue is the memory controller, very likely the DRAM can not do it. Test on another board to be certain. Test two sticks at 800 with 4-4-4-12 and see what happens. The 1066 is not tested at 800 with 4-4-4-12. Usually it can make it but it's not tested and I have found 1066Mhz 5-5-5-15 that will not make 800 4-4-4-12 but will make 800 5-5-5-15.

 

You probably just got unlucky with your DRAM. It's the luck of the draw. I've been unlucky as well.

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Both pairs passed the 800Mhz with relaxed 5-5-5-12-2T timings without errors. I am trying the 4-4-4-12-2T @ 800Mhz next. I can't believed I am having such a bad luck with RAM. This is the second set that doesn't over clock well for me. Believe it or not but I spend $600 on this RAM a while back, just to overclock it later and bummer. I may try this RAM on my friends system as well. I appreciate all of your help guys. I will let you know how the 4-4-4-12-2T test will go.
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Both pairs have passed the 4-4-4-12-2T timings. This was done with fsb at 200Mhz and multiplier of 10. So does this mean that my RAM is fine? I will try to slowly increase the FSB to see how far I can go with timings of 4-4-4-12-2T. Once unstable what settings do you recommend I adjust in BIOS to make it more stable? Is it possible that my memory controller is still bad? Where is the memory controller located anyway the CPU the motherboard, or in both? Thank you for helping me this far. :):
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Both pairs have passed the 4-4-4-12-2T timings. This was done with fsb at 200Mhz and multiplier of 10. So does this mean that my RAM is fine? I will try to slowly increase the FSB to see how far I can go with timings of 4-4-4-12-2T. Once unstable what settings do you recommend I adjust in BIOS to make it more stable? Is it possible that my memory controller is still bad? Where is the memory controller located anyway the CPU the motherboard, or in both? Thank you for helping me this far. :):

 

The memory controller is located on the CPU die. It's not bad, but they are a bit wonky when it comes to higher end speeds and maximum capacities. Once unstable, lower a bit, test for stability and leave it there. I already gave you the voltages necessary. I would not increase higher than given. Lower the timings and see what you get. That DRAM is warranted for up to and including 2.1v. Any higher and you forgo your warranty and the DRAM will show overvoltage characterstics.

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