GA-P55M-UD4 and G.Skill Trident or PIS memory.

[EFS_Junior]

Need help in getting PC3 16000 (DDR3 2000 MHz) or faster memory for a GA-P55M-UD4 MB.

Currently have an i7-860 OC'd to 4GHz with 8GB of F3-12800CL9D-4GBNQ (two 4GB kits), BCLK = 200 MHz, and CPU voltage is 1.38750V.

From Gigabyte's recommended list the Trident PC3 16000 (DDR3 2000) will work with my MB;

G.SKILL Trident 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 2000 (PC3 16000) Desktop Memory Model F3-16000CL9D-4GBTD

Given the fixed memory multipliers for my MB (6X, 8X, 10X, 12X) and the BCLK = 200 MHz would seem to suggest memory rated in multiples of 400 MHz?

Does using XMP memory profile(s) get around this fixed memory multiplier issue?

Finally, I'm currently looking at faster G.Skill PIS and Trident memory, does anyone have direct experience with the following memory modules on the GA-P55M-UD4 MB?

G.Skill PIS (or PI Series);

DDR3 2200 (PC3 17600) Desktop Memory Model F3-17600CL7D-4GBPIS

DDR3 2300 (PC3 18400) Desktop Memory Model F3-18400CL8D-4GBPIS

DDR3 2133 (PC3 17066) Desktop Memory Model F3-17066CL7D-4GBPIS

DDR3 2000 (PC3 16000) Desktop Memory Model F3-16000CL6D-4GBPIS

DDR3 2400 (PC3 19200) Desktop Memory Model F3-19200CL9D-4GBPIS

DDR3 2200 (PC3 17600) Desktop Memory Model F3-17600CL7Q-8GBPIS

G.Skill Trident;

DDR3 2133 (PC3 17066) Desktop Memory Model F3-17066CL9D-4GBTDS

DDR3 2133 (PC3 17066) Desktop Memory Model F3-17066CL9Q-8GBTDS

Any help from anyone will be greatly appreciated, TIA.

[GSKILL TECH]

The multipliers are based off the BCLK.

So BCLK 200 x 12 = DDR3-2400

This will be your safest max. Anything above will require further tweaking.

So... as far as I can tell all the ones above are below DDR3-2400, so you just need to close your eyes and point to one to purchase. =)

Thank you
GSKILL TECH

[EFS_Junior]

OK, thought so.

So either DDR3-2000 (10X) or DDR3-2400 (12X) will work, while the rest will work at DDR3-2000 for a BCLK of 200MHz (with additional headroom that may OC to DDR3-2400).

The reason I'm asking, is that reading on the web, appears to suggest that higher speed memory will lead to more stable OC'ing at higher multipliers (I'm at 20X now with the maximum possible of 22X).

Is there any truth to the above statement?

Don't expect much of a real world speed improvement sans a higher CPU multiplier (21X or 22X).

My current goal is 21X (4.2GHz) for an OC of 50% (BCLK of 200MHz). I currently have too high CPU thermals to reach 4.2GHz safely, I'm hoping that faster memory will get me to this goal, and I realize that there are no guarantees regardless.

Looking at just the PIS series;

F3-19200CL9D-4GBPIS (CAS Latency 9-11-9-28-2N)
F3-18400CL8D-4GBPIS (CAS Latency 8-11-8-28-2N)
F3-17600CL7D-4GBPIS (CAS Latency 7-10-10-28-2N)
F3-17600CL7Q-8GBPIS (CAS Latency 7-10-10-28-2N)
F3-17066CL7D-4GBPIS (CAS Latency 7-10-7-27-2N)
F3-17066CL7Q-8GBPIS (CAS Latency 7-10-7-27-2N)
F3-16000CL6D-4GBPIS (CAS Latency 6-9-6-24-2N)
F3-16000CL7D-4GBPIS (CAS Latency 7-9-7-24-2N)
F3-16000CL8D-4GBPIS (CAS Latency 8-9-8-24-2N)
F3-16000CL9D-4GBPIS (CAS Latency 9-9-9-24-2N)

Suggests some CAS Latency headroom (backing off of the faster timings to either 9-9-9-24-2N or 9-11-9-28-2N) to either speed up (DDR3-2000) or slow down (DDR3-2400) these timings to obtain stable OC'ing.

I'm also somewhat concerned about getting 2-4GB kits versus 1-8GB kit after reading this forum.

In the end, I think I'll get the F3-16000CL9Q-8GBTD Trident kit from Newegg ($325.98 including shipping) or two F3-16000CL9D-4GBTD kits ($277.98 with free shipping) this weekend, as this is currently approved for the Gigabyte GA-P55M-UD4 MB, has been around for a while, and appears to have the most favorable reviews at this point in time.

Thanks for the help and you people make great memory!

[GSKILL TECH]

The reason I'm asking, is that reading on the web, appears to suggest that higher speed memory will lead to more stable OC'ing at higher multipliers (I'm at 20X now with the maximum possible of 22X).

No, not quite, but in a sense. People always have this idea that higher memory ran at a lower frequency is better than memory that is operating at specifications. It is obviously a higher performance kit, but DDR3-1600 CL7 with a DDR3-2400 kit is the same as DDR3-1600 CL7 with a DDR3-1600 CL7 kit. It is not any better or faster simply because it was originally a DDR3-2400 kit. In fact, some DDR3-1600 CL7 kits are capable of DDR3-2000+. When it comes to overclocking CPU, GPU, memory, computer hardware, it is just about finding the right voltage at a particular frequency. Of course there are always limits, but as overclockers know, you can easily push hardware past rated limits if done correctly.

My current goal is 21X (4.2GHz) for an OC of 50% (BCLK of 200MHz). I currently have too high CPU thermals to reach 4.2GHz safely, I'm hoping that faster memory will get me to this goal, and I realize that there are no guarantees regardless.

Faster memory will not decrease your CPU temperatures. High memory frequency will always cause high CPU temperatures which is why DDR3-2000+ requires aftermarket CPU coolers. To run 4.2GHz with DDR3-2400, we use a huge CPU cooler like the Thermalright Ultra or Dark Knight to keep the CPU cool. Otherwise water cooling would work too.

The Trident kit is great, but actually with any of these kits, you will be very satisfied.

Thank you
GSKILL TECH