Motherboard Memory compatibilty

brianthethird

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Feb 23, 2010
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HI all,

Assembling my first PC, so I have all the parts ready, or so I thought when I realized that the motherboard manual flat out doesn't include the frequency of the memory I bought. It was advertised as ""DDR3 up to 2200 MHz" I also am confused about weather I can install 3 x 2 gigs (because I have three memory sticks) and if the voltage will be an issue (on the memory it says 1.65 V and the mother board manual states 4 x 1.5 V)

This is the mother board I got
http://www.gigabyte.us/Products/Motherboard/Products_Overview.aspx?ProductID=3254 (GA-P55A-UD3 (rev. 1.0))
and this is the memory
http://www.google.com/products/catalog?hl=en&rlz=1C1GGLS_enUS349US349&q=XMS3+corsair+TR3X6G1600C9&oq=&um=1&ie=UTF-8&cid=2814033248658171530&ei=lqOES_ChH4GYtgfowsXxAg&sa=X&oi=product_catalog_result&ct=result&resnum=3&ved=0CBwQ8wIwAg#ps-sellers

To summarize:
1. Is the frequency going to be an issue for the motherboard?
2. Is it ok to have 6 gigs?
3. Is the voltage going to be an issue (motherboard states 1.5V while the memory requires 1.65V)

I would appreciate the response. I fear I have made a mistake and want to confirm before I have to return the memory.
 
Solution
and do they even make ddr3 at 800 mhz? that is wierd

well anyway your ram will default to 1333 and you will have to manualy set it to 1600 in your bios you should be able to do so without changing anything else as i have a gigabyte board as well and had to do the same thing good luck

darkjuggalo2000

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Jan 29, 2010
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that board will support that memory with no problem........ 6gigs will work... and no the voltage should not be an issue although you will have to manually set the frequency in the bios upon startup from 1333 to 1600 good luck
 
D

Deleted member 217926

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That is a good MB I just used one in a build with an i5 750 a few weeks ago.

This is a P55 chipset board and it only supports dual channel memory. You bought a triple channel memory kit that would be better used by an x58 chipset motherboard. That being said all 3 sticks will run fine but you would have to add a stick or only run 2 to have dual channel benefits.

Also in BIOS you would need to manually adjust the RAM voltage to 1.65.
 

brianthethird

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I was worried because in the mobo manual it stated: "Support for DDR3 2200/1333/1066/800 MHz memory modules " So if 1600 wasn't a choice I wasn't sure if I could configure the motherboard to that choice.
 

darkjuggalo2000

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Jan 29, 2010
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and do they even make ddr3 at 800 mhz? that is wierd

well anyway your ram will default to 1333 and you will have to manualy set it to 1600 in your bios you should be able to do so without changing anything else as i have a gigabyte board as well and had to do the same thing good luck
 
Solution
D

Deleted member 217926

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As I stated above I just used an identical board in a recent build. I forgot to mention that you need to do a BIOS update as soon as you can. Many of the monitoring programs I use like PC Wizard 2009 , CPUZ and Speedfan had problems identifying the board and reading sensors before the update.

All around solid Gigabyte BIOS after the update. Like any Gigabyte board while on the main BIOS screen you can use Control + F1 to unlock extra options.
 

ekoostik

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It depends on which CPU you got. With an i7 860 or i7 870, you can run at speeds of up to 1600 MHz without OCing your CPU. With an i5 750 or a Clarkdale CPU the fastest speed you can run at without OCing is 1333 MHz.
 

ekoostik

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It's interesting, though not surprising, that they've listed the 860 memory types as 1066/1333. I say interesting because most P55 motherboards (would be good to get confirmation on the H55/H57 chipsets) enable an extra multiplier for the i7 8xx memory SPDs. Is this not listed in any Intel spec? It's not something the motherboard manufacturers decided to allow - is it? If so, why not also allow it for the i5 750s?
 

bilbat

Splendid
There are thirty-two clock signals defined for the 5 and 3400 series PCHs, which include:
P55, H55, H57, Q57, PM55, QM57, HM55, HM57, QS57, and the 3400, 3420, and 3450 - not one is a memory clock - that's why the terminology has changed from MCH to IOH or PCH...

The processors are very flexible for rank/bank configuration, but, for the main part, 'agnostic' about physical memory clocking...

The few register-level controls that aren't define:

MC_DIMM_CLK_RATIO_STATUS
This register contains status information about DIMM clock ratio.

Device:3
Function:4
Offset:50h (Access as Dword)

bit 28:24 MAX_RATIO. Maximum ratio allowed by the part.
Value = Qclk
00000 = RSVD
00110 = 800MHz
01000 = 1066MHz
01010 = 1333MHz

bit 4:0 QCLK_RATIO. Current ratio of Qclk.
Value = Qclk.
00000 = RSVD
00110 = 800MHz
01000 = 1066MHz
01010 = 1333MHz

and:
MC_DIMM_CLK_RATIO
This register is for the Requested DIMM clock ratio (Qclk). This is the data rate going to the DIMM. The clock sent to the DIMM is 1/2 of QCLK rate.

Device:3
Function:4
Offset:54h (Access as Dword)

bit 4:0 QCLK_RATIO. Requested ratio of Qclk/Bclk
00000 = RSVD
00110 = 800MHz
01000 = 1066MHz
01010 = 1333MHz

Are the 'reserved's the key - ?? - still digging!