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Gigabyte P55-UD4P -- Can't get DDR-1600? Help?

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Nov 30, 2009
Hey guys,

Run a solid setup.. I'll list some components just to give you an idea.. then maybe you can address the question or point me in the right direction.

PSU - Corsair TX850W
Video - Radeon 5850 HD 1GB
RAM - 2GBx2 (4GB) OCZ 12800 DDR3-1600 (9-9-9-24 @ 1.65v)
HDD - Seagate Barracuda 7200.12 1TB
Motherboard - Gigabyte P55-UD4P (11/20/2009 F5 Bios)

CPU - Intel i5 750 Lynnfield OC'd 3Ghz Quadcore
Optical - Lite-On Blu-Ray, CD/DVD Writer AIO
Case - Rosewill Wind Knight Gaming ATX Mid Tower

That is enough, you get the idea of the box.. Solid , running Win7 64bit, liking it just ironing out some bugs.

One of which is getting the 1600 Rated 'default' ram to run at 1600.

The board puts it at 1066 .. this is of course at an SPD of 8.

In the Award bios on the Gigabyte UD4P it has options of an SPD of 6.0, 8.0 , or 10.0. I need 12.0 to hit the 1600 advertised.

This the MB's fault here? Should it have a 12x multi there.. ?

Or is there something I'm missing?

I went ahead and tried to clock it at 9-9-9-24, at 1.66v (board has 1.64v and 1.66v.. no 1.65v (doesn't like odd numbers? I dunno).. and set the BCLK to 160, with SPD at 10 .. which would be 1600.. (also 3.2Ghz at 20x OC on the proc) -- Proc handled it fine.. in Prime95 the memory failed terribly.

I even lowered some further timings like Command rate to 2, and trc to 45, and trfc to 90.. let Prime95 go a bit longer, but still crashed.

I'm at a loss.

This something I Need to RMA and get other sticks ... it the boards bios fault, and needs another bios revision flash to get right.. maybe some settings I'm missing. (I'm sure someone has a P55-UD4P and some 1600 Ram..) -- Not like I am talking about some weird unpopular components.. its Intel proc with OCZ RAM.

Anyhow,.. any and all advice / tips is much appreciated!



Inactive Moderator
Dec 17, 2000
Portland, OR
In order to run the RAM at it's rated 1600MHz, you'll need to raise the BCLK to 160MHz and drop the multiplier accordingly. Max. rated memory speed for the i5 is DDR3-1333MHz, which is why there are no higher multiplier options than 10x. With a BCLK of 160MHz running a 2:10 DRAM ratio (System Memory Multiplier / SPD of 10), the effective DRAM frequency is 1600MHz. Try dropping the multiplier to 18x for a 2.88GHz clock speed. Then enable XMP mode (Extreme Memory Profile) for DDR3-1600MHz. Or just adjust the four primary timings to 9-9-9-24 at either 1.64V or 1.66V DRAM voltage (whichever voltage is required to pass Memtest86+), and leave all sub-timings on AUTO.
Last edited:


Nov 30, 2009
Interesting,.. Seems fairly odd they would limit it to 1333 on the i5 that was released Q3 of this year,.. Doesn't make alot of sense, it is a state of the art chip. Easy runs 16Ghz (combined, yes I know it doesn't equate quite that way :) ).. Nonetheless.. 1333 to 1600 isn't a very large difference from benchmarks done anyhow, it is just rated as that and I suppose just figured it would have no problem running.

Just doesn't seem proper the i5 limiting the ram capability on a board and socket that runs both the i5 and i7.. Fastest things out there.

Anyhow,.. I did mention already I put the BCLK at 160, at 2:10, with SPD of 10.. no go.

Now dropping the FSB Multi 2-3 notches is an interesting idea.. for 'xmp mode' -- What exactly is this xmp mode? Mind explaining it at all?

I'm already running 3Ghz on the nose with stock cooling, at 143 x 21 -- with Ram at 8 x 141, 7-7-7-16, 1.5v (The board on auto sticks it at 1.5, and I don't know why.. when I manually stick it to 1.64, or 1.66 it isn't stable) shrug. This 3Ghz is very stable.

I am going to nab a good aftermarket cooler, and clock even higher, which will net higher memory speeds.. so I think I am just going to settle for whatever results with the FSB x Multi at 8x (the auto SPD).. see what happens, cause timings are great there..

I would anticipate 7-7-7-16'ish at 1250-1400 is probably better performing than 1600 at 9-9-9-24 or even loser timings, like CR at 2t, and so on.

Shocker, limited to 1333 on Intels June release chip. Oh well, is what it is.. Still should pick up at 1333 auto from bios without a single tweak imo, not 1066. Bios on the UD4P still needs revisions to correct some of this, and I'm not so sure a 12x SPD wouldn't 'not work',.. why not? Though I'm certainly not a computer engineer.. I am a computer scientist, but I don't engineer them.

Thanks .. and any more comments are more than welcome.

P.S. -- I also wouldn't have any better luck with any other ram (this ram was 100$ for the 4GB) .. good deal at newegg.. I mean any ram that isn't 2-3-400$. It seems the voltage on this ram is a touch high for what the P55 chipset likes to use. The P55 likes lower voltages across the board, literally. From Vcore to VDD. Comparing to AMD specs, even your Q813A and RAM specs.. the voltages are way higher . But with different tech comes more power with less power off the main board anyway. Still a 95w CPU.


Nov 30, 2009
Well.. I've put the system on a water cooled system (OOB anyway). Dropped temps 40 degree's.. mighty impressive.

However, I can break 4Ghz on the cpu now easily.. but the RAM just doesn't like anything much over 150 x 10. I don't know why either,.. but the RAM is why prime95 fails, or memtest obviously at even such settings as 160 x 10.. when I can load in something like:

200 x 21 for 4.2Ghz, at PC-1066 speed ram and run stable.


Lots of power on tap here, limiting factor is this RAM, although it is fast even at 1450-1550ish, very fast, so I shouldn't be complaining.. but I'd like to run my FSB above 160 and above and run the ram at 1600 -- Cause the RAM is designed to do it. The RAM won't do 1600 in any configuration over or underclocked.

Now I haven't tried 100 x 16 , or 200 x8 lol.. But you know what I mean.

Would more expensive RAM be more likely to run at these speeds.. or is it this MB being finicky?