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to SLI or not to SLI


mycorr

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The SPD on the Corsair memory I have is set to 5-5-5-18 and 800 MHz, so that's what my mobo is running it at since it's set to AUTO. However, the .pdf states that the memory has been tested for 4-4-4-12 at 2.1 V, and I'm assuming that's at 800MHz as well.

 

My question is: should I set my mobo to those settings (can it even handle them?), or should I enable SLI?

 

Thank You.

 

 

P.S. This is on Vista Home Premium 32 bit, if it makes any difference.

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The SPD on the Corsair memory I have is set to 5-5-5-18 and 800 MHz, so that's what my mobo is running it at since it's set to AUTO. However, the .pdf states that the memory has been tested for 4-4-4-12 at 2.1 V, and I'm assuming that's at 800MHz as well.

 

My question is: should I set my mobo to those settings

 

 

There is a standard for DRAM. The JEDEC DRAM standards. These standards give 800Mhz with 5-5-5-18 at 1.8v. Any DRAM of higher speed and lower latencies are above the JEDEC Standards. Your SPD sets to the JEDEC or EPP (Extended Performance Profiles).

 

I found this Corsair lab test. It says that the board detected the memory as 4-4-4-12 and 800MHz. Mine didn't, so I'm not sure what to make of this now. Anyone know what's going on?

Thanks

 

Some don't and then you just manually enter the settings.

 

Enter your BIOS and set:

 

Multiplier = 9

FSB = 266

DRAM = Unlinked and set to 800Mhz

 

Memory Timing

 

FSB - Memory Clock Mode: Unlinked

CPU FSB: 266

CPU Multi: 9

DDR FSB: 800

tCL: 4

tRCD: 4

tRP: 4

tRAS: 12

 

Advanced Memory Settings

 

tRRD: Auto

tRC: Auto

tWR: Auto

tWTR: Auto

tREF: Auto

Async Latency: Auto

CMD: 2T

 

CPU Spread Spectrum: Enabled

PCIE Spread Spectrum: Enabled

MCP PCIE Spread Spectrum: Enabled

SATA Spread Spectrum: Enabled

LDT Spread Spectrum: Enabled

 

CPU Internal Thermal Control: Enabled

Limit CPUID MaxVal: Enabled

Enhanced C1 (C1E): Enabled

Execute Disable Bit: Enabled

Virtualization Technology: Enabled

Enhanced Intel Speedstep Tech: Enabled

LDT Frequency: 5x

 

PCIEX16_1 Frequency (Mhz): Auto

PCIEX16_2 Frequency (Mhz): Auto

PCIEX16_3 Frequency (Mhz): Auto

SPP<->MCP Ref Clock, Mhz: Auto

 

Voltages

 

Vcore = Auto

Vdimm (DRAM Voltage) = 2.1v

1.2v HT: Auto

NB Vcore: Auto

SB Vcore: Auto

CPU VTT: Auto

 

You must now test for DRAM stability. Download memtest from http://www.memtest.org and extract the ISO image. Burn the Image to an optical disk and boot to the optical drive. Let the program run for two full passes. If it comes clean, then you are DRAM stable.

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Thanks DerekT,

 

I just checked CPU-Z and it reported: FSB:DRAM = 2:3 and memory frequency = 400MHz. I've left everything on auto; why wouldn't the mobo be set at 800Mhz?

 

Is there anything else I should know in light of this before I go ahead with what you prescribed? This is all pretty new to me, I appreciate your help.

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Thanks DerekT,

 

I just checked CPU-Z and it reported: FSB:DRAM = 2:3 and memory frequency = 400MHz. I've left everything on auto; why wouldn't the mobo be set at 800Mhz?

 

Is there anything else I should know in light of this before I go ahead with what you prescribed? This is all pretty new to me, I appreciate your help.

 

Your 400MHz DRAM in the Memory Tab of CPU-z when showing 400Mhz needs to be multiplier by 2 for Dual Channel Mode. Thus 400Mhz actually means 800Mhz Dual Channel Enabled.

 

I run my memory at 570Mhz in the CPU-z Memory Tab, and this gives me 1140Mhz in Dual Channel Mode. All you need to do is set the Vdimm (Dram Voltage) and the timings and then test with Memtest.

 

You are at 800Mhz.

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Now I understand, thanks again.

 

I just tried memtest86 1.70 without changing anything. It was still going when I stopped it; it said it was doing test #6 and was still counting walltime. Just to be sure before I go ahead and do the test after changing the BIOS settings: I'm wondering if memtest actually did six full passes, or if the test takes a long time and that when I stopped it, it was only at test 6 of however many make one full pass? Thank You.

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Ok, so memtest does take a while.

 

 

I checked my BIOS and found that:

 

PCIEX16_1 Frequency (Mhz): 100

PCIEX16_2 Frequency (Mhz): 100

PCIEX16_3 Frequency (Mhz): 100

SPP<->MCP Ref Clock, Mhz: Auto

 

I can't set PCIEX16_ frequencies to Auto, I can only set between 100-200.

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It didn't POST! and I almost forgot to reset RAID!!!

 

 

There were however some differences in our menus:

 

- the PCIX16_ frequencies set to 200MHz from 100MHz as you know

 

- CPU Spread Spectrum could only be set to disabled or auto, i left it on auto

- this kept both PCIE Spread Spectrum and MCP PCIE Spread Spectrum greyed out and set to disabled

- SATA Spread Spectrum could only be set to disabled or auto, i switched it to auto

 

- CPU Internal Thermal Control could only be set to disabled or auto, i left it on auto

 

 

Everything else, I'm certain, was as you prescribed.

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Three things I didn't mention:

 

1- when it failed to post it beeped: once long then three shorter beeps

 

2- the one voltage i switched from auto to 2.1V was not called Vdimm (DRAM voltage), it was called Memory

 

3- my FSB and memory menu is different;

 

it's titled: FSB & Memory Configuration

FSB - Memory Clock Mode: i changed it from auto to unlinked

FSB (QDR), MHz: i left it at 1066 (could have been 533-3000)

MEM (DDR), MHz: i left it at 800 (could have been 400-2600)

 

 

I assume it's the quad core difference.

 

So, any ideas?

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You might well have to set the 800MHz DRAM to 667 due to populating all four DRAM banks. Often this is the case of instability on both Nvidia and Intel based solutions.

 

Your other settings were correct :)

 

Do you have IM? If so, please PM me with your IM and I will contact you via messenger.

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Missed that last reply, no I don't have IM.

 

Should my next step be to 667? or should I be satisfied with 5-5-5-18?

OR turn on SLI??

 

Can you find stability with 5-5-5-18 and 800Mhz? It is not good to turn on SLi because that DRAM does not have SLi characteristics.

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The package says, SLI-Ready.

 

My mistake. Sorry. I was helping someone with 6400 (non-sli) and I extended it to you.

 

You can, if you wish, enable SLi. I do not in the systems I build as it has proven to be inconsistent and manual settings are "set in stone" as it were :).

 

It's your choice though. Can you manually set them to 5-5-5-12 and find stability?

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No Worries. Also, I don't think it says SLI-Ready on the pdf. I heard bad things about SLI but keeping hoping someone will tell me it's great.

 

I have no idea if i can find stability with those timings. Would I have to change anything else? How much of a difference would it make?

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