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Help with TWIN2X4096-8500C5D and GA-EP45-UD3P


GearJunkie

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I’m new to this, so please bear with me…

 

I just switched from a BadAxe2 to the Gigabyte board in the specs. I was hoping to reuse my 2 sets of Twin2X2048-5400C4, but the latest versions of Memtest+ and Memtest86+ crash immediately, or don’t even begin. Individually, each set checks out ok, in either set of slots in the board, so I know the memory itself is not bad. I checked under the Corsair memory configurator and see that these modules don’t come up, so I ordered some TWIN2X4096-8500C5D. These are listed as being compatible on Corsair’s site and Gigabyte’s site, so they should work out ok.

 

I would like to continue to run the CPU at 9x300MHz for a mild overclock (2.7 GHz), or maybe even 9x333MHz (3GHz). The memory modules are rated way higher than this though, so can someone please help me out with the settings?

 

The computer will be used for a Photoshop workstation, so stability is of utmost concern. I appreciate any help.

 

Thanks!

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The only memory Corsair supports in a four DRAM slot population is their Quad kits. This does not mean two dual kits or even worse two dual kits of different versions and models will not work together, just that you have no recourse to RMA Corsair if they do not work together. If there are problems with the DRAM modules, they are still supported via lifetime warranty, but that is for physical defects and errors in a two stick kit mode. Matched Quad sets are highly binned modules for a four slot population. The Dual sets are tested as a kit, not a Quad and warranted as a dual kit, not a Quad setup. You need to Memtest them as Kits (2 modules, not as a four DRAM slot population). If they fail as a kit or singly, then you have RMA. Keep in mind that there is no support for mixing and matching different versions of DRAM either since different version are of different fabrications and/or manufacturers. They might work, they might not work, but you have no support if they do not work.

 

For a four DRAM slot population of 1066Mhz DRAM you are advised to drop the bandwidth to 800Mhz and raise the NB 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 or On CPU (AMD) 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. It does not mean that you can't get the board to work at full speed, just that some do and some do not. Some do not even accept four DRAM sticks even dropped to lower speeds. These boards need to be RMA'd.

 

My advice would be to use 2GB sticks and sell the 1GB sticks. However, you can try to use them all though with a drop in bandwidth from 1066Mhz --> 800Mhz and a raise of the memory controller's voltage +.2v.

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Thanks for the info! I do only plan to use only 2 sticks of the TWIN2X4096-8500C5D. I just need some help setting up the timings for 9x300 and 9x333.

 

I would also be interested in using 7x400, if possible??? But I thought I remember reading that it's not a good idea to change the CPU multiplier.

 

Thanks again!

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Do you have the FPO/Batch code for your CPU? It will be on the box (White Sticker).

 

Thanks for the info! I do only plan to use only 2 sticks of the TWIN2X4096-8500C5D. I just need some help setting up the timings for 9x300 and 9x333.

 

I would also be interested in using 7x400, if possible??? But I thought I remember reading that it's not a good idea to change the CPU multiplier.

 

Thanks again!

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Since I'm going for stability/longevity, I would really prefer to run at 7.5x800. But aren't there issues with running with half-multipliers?

 

Also, I want to run the CPU and Memory at 1:1, to avoid any ratios. Can you explain (or point me to an article) that explains the current deal with ratios and the strap?

 

Thanks!

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You will have no issue in the longer term with 8 X 400 = 3.2Ghz. Seriously. That's such a tiny increase in voltages and very possibly with your CPU it is still not anywhere near Intel's SPec of max at 1.35v.

 

Your north bridge has an internal clock speed and latencies just like your CPU and memory. The FSB of your north bridge can be found by dividing your original CPU multiplier by your set CPU multiplier and then multiplying by your FSB.

 

So if you are running a E6600 (266 * 9) at 400Mhz x 8 your NB FSB is:

 

(9 / 8) x 400 = 450Mhz FSB (1800Mhz Total)

 

Just like your memory may be able to run at 4-4-4-12 at 1000Mhz but needs to run at 5-5-5-15 at 1200Mhz, your north bridge has a series of latencies which it must adjust in order to maintain stability at its FSB. These latencies seem to play a far more significant role in system performance than memory latencies.

 

Intel has predefined specific NB latencies at specific NB FSB speeds. They are referred to as straps. There is a strap for when the NB FSB is 1066Mhz and under, 1333Mhz FSB and under, 1600Mhz FSB and under, etc. When you go from the 1066Mhz FSB strap to the 1333Mhz FSB strap, the north bridge's internal latencies loosen to allow for greater stability.

 

ASUS has redefined the NB strap so that the 1333Mhz FSB strap does not come into effect until 401Mhz FSB (1604Mhz). Other perimeters of straps are somewhat unknown.

 

There are 2 ways to beat the NB strap:

 

1. Boot to windows in the 1066Mhz strap and then use Clockgen to increase your CPU's FSB. You can then get to a much higher FSB while maintaining the 1066Mhz strap simply because the BIOS does not adjust the north bridge's latencies in real time.

2. Get a X6800 or QX6700 (or even a ES chip). To the north bridge, you are always at a default multiplier with a Extreme Edition processor. This allows you to set a much lower or higher multiplier without the NB FSB being effected.

 

CPU Ratio is the multiplier that when tied to the FSB gives you your speed. CPU Ratio = 9 and FSB = 266. 266 X 9 ~= 2.4Ghz which is the value of your E6600. You overclock by raising your FSB. Many Extreme Edition CPUs have an unlocked multiplier and allow you to raise your FSB and your multiplier. Locked Core2 CPUs allow you to lower the default multiplier. E6600 for example has a default multiplier of 9 and you can drop this to 8, 7, and 6 if you wish, but you already know most of this information.

 

Since I'm going for stability/longevity, I would really prefer to run at 7.5x800. But aren't there issues with running with half-multipliers?

 

Also, I want to run the CPU and Memory at 1:1, to avoid any ratios. Can you explain (or point me to an article) that explains the current deal with ratios and the strap?

 

Thanks!

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