F3-14900cl9d-8gbxl

[Centora]

I have a question about the Ripjaws X Series DDR3 1866Mhz (PC14900) 8GB dual channel RAM with sku of F3-14900CL9D-8GBXL. I plan to use these ram modules with an AMD Phenom II X4 955 cpu with a bus speed of 1333Mhz. The reason for this is to in-the-future (3 or 4 years from now) run an 8-core CPU having a bus speed of 1866Mhz.

The question is... since the 955 CPU is a Black Edition should I set the RAM speed in bios as 1333Mhz, raise the FSB so that the RAM runs at the rated 1866Mhz, and change the CPU Multiplier down to accommodate for this change? Doing so however would result in an OC of the chipset. Another option I have is to set the RAM to run at 1866Mhz and the CPU at 1333Mhz however I'm not sure if this is possible or if it would lead into stability issues. Last option I have is to run the RAM at 1333Mhz and tighten the timings (if this option is chosen any chance you would know the appropriate timings to set?).

Since it's a gray area for me when it comes to DDR3 which would get me the most out of my system/best performance? Intention here isn't to overclock/over-spec anything. Just saying it would be a shame to pay $20 more for 1866Mhz RAM and run it as 1333Mhz RAM with default timings.

System specs:
RAM: G.SKILL Ripjaws X Series 8GB (2 x 4GB) DDR3 SDRAM DDR3 1866 (PC3 14900) 9-10-9-28 @ 1.5v Timings
CPU: AMD Phenom II X4 955 Black Edition Deneb 3.2GHz Socket AM3 125W
Mobo: ASRock 990FX Extreme3 AM3+ AMD 990FX

[GSKILL TECH]

You should use the DDR3-1600 multiplier instead, which is x8.00

Set CPU Host (bus) frequency to 233

233 x 8 = DDR3-1864

Set CPU Frequency to desired ratio; 15X should put you around 3.50GHz, 14X puts you around 3.26GHz

Set CPU-NB Frequency to 2796MHz

Set CPU-NB Voltage to 1.20V

Set DRAM Voltage to 1.50V

Set timings to tCL 9 - tRCD 10 - tRP 9 - tRAS 24

F10, save, exit, enjoy, then come back to tell us how well it went.

Thank you
GSKILL TECH

[Centora]

You should use the DDR3-1600 multiplier instead, which is x8.00

Set CPU Host (bus) frequency to 233

233 x 8 = DDR3-1864

Set CPU Frequency to desired ratio; 15X should put you around 3.50GHz, 14X puts you around 3.26GHz

Set CPU-NB Frequency to 2796MHz

Set CPU-NB Voltage to 1.20V

Set DRAM Voltage to 1.50V

Set timings to tCL 9 - tRCD 10 - tRP 9 - tRAS 24

F10, save, exit, enjoy, then come back to tell us how well it went.

Thank you
GSKILL TECH

Okay I set the CPU ratio to 14x because I don't really want to run out of spec. Also this is my 24.7 rig is it really safe for the long-term to run the NB 0.10v higher than default and a 33Mhz overclock? I mean this board can be set to 1866Mhz leaving the FSB @ 200Mhz because it's designed for the new bulldozer having an 1866Mhz memory bandwidth. I believe 1866Mhz setting is 9x CPURAM multi giving me 1800Mhz ram. Still don't realy want to run the NB higher but could also set it to 207Mhz giving me 1863Mhz ram.

I'm not saying your wrong at all as this would do the trick however in long-term scenario would your suggestion be ideal? Whichever is by far the most stable to run 24.7 at keeping all components at spec.

The whole reasoning behind getting 1866Mhz ram is not to get a performance boost over 1333Mhz ram. If I was going for performance I'd just have gotten ram rated at 1333Mhz with certified tighter timings. Reason I got the 1866Mhz ram is to upgrade to the FX line of processor in 2 to 3 years from now after a few revisions come out and price/hype over them drop. On that same token however I'm not going to pretend all I have is 1333Mhz ram and not get full benefit out of it.

[Tradesman]

Biggest problem you may run into with the sticks is your CPU, the 955 can have problems even running 1600, I generally recommend at least a 965 for 1600, so to push them to 1600 and above generally requires extra DRAM and/or CPU/NB voltage

As an aside, buying something now like this in the idea of upgrading CPUs in 2 or three years is sort of self-defeating....the current top of the line Dozer the FX 8150came out higher priced that the 92500K yet can't keep up with the Intel chip head to head, doesn't OC as well and still is lacking at the (MC) memory controller end.......and Ivy Bridge is around the corner, where Intel will be even faster and looking for DRAM that doesn't even exist yet, 2800 sticks and better.

[Centora]

Biggest problem you may run into with the sticks is your CPU, the 955 can have problems even running 1600, I generally recommend at least a 965 for 1600, so to push them to 1600 and above generally requires extra DRAM and/or CPU/NB voltage

As an aside, buying something now like this in the idea of upgrading CPUs in 2 or three years is sort of self-defeating....the current top of the line Dozer the FX 8150came out higher priced that the 92500K yet can't keep up with the Intel chip head to head, doesn't OC as well and still is lacking at the (MC) memory controller end.......and Ivy Bridge is around the corner, where Intel will be even faster and looking for DRAM that doesn't even exist yet, 2800 sticks and better.

The 965 CPU isn't the ideal chip due to the fact that it came out before the 955 so uses the older design @ 140 Watts. So yes the specs lie when it lists an 965 @ 125 Watts. Whats the big deal? Well AM3/AM3+ boards are rated at 140 Watts maximum for the socket leaving no headroom to overclock the chip and possibly even blow the power phase on the motherboard running at stock.

I realize running the sticks at even 1600Mhz would cause issue because 1333Mhz is the ideal. That's why I came to the manufactures website in hope to get the appropriate memory timings running the 1866Mhz sticks at 1333Mhz. I know that's all you guys do is interchange the modules. Stick A could be 1866Mhz OR 1333Mhz with better timings sold at the same price with different model numbers. That's why I can run my PC6400 5-5-5-20 modules @ 1000Mhz 4-4-4-12 with default voltages. Very good ram company and you guys caused me to witch from k*ngston.

As for my idea to be self-defeating... Totally agree with you that i2500k > FX-8150 any day of the week. However I have the budget of $120ish for the CPU and wasn't going to get an i3 because I already have a dual-core FX 64. That said I'm going the route of X4 955 now and upgrading to the FX-8150 or better AM3+ cpu in 2-3 years. Only way I'd get the i2500k is if they run a sale on this Black November campaign.

So ram settings for these modules @ 1333Mhz?

[Tradesman]

Those can prob run between a tight 7-7-7-22 or a slight looser 8-8-8-25, with either at 1.5 (possibly a bit higher for the CL7)....believe CPU/NB will prob work on Auto, but again may have to raise slightly for the CL7 (poss + .03/4). With the CL8 setup you can prob cut the CR to 1N which would give a bit of a boost. Might also want to make sure you have the latest BIOS

[Centora]

Those can prob run between a tight 7-7-7-22 or a slight looser 8-8-8-25, with either at 1.5 (possibly a bit higher for the CL7)....believe CPU/NB will prob work on Auto, but again may have to raise slightly for the CL7 (poss + .03/4). With the CL8 setup you can prob cut the CR to 1N which would give a bit of a boost. Might also want to make sure you have the latest BIOS

Okay thank you for the fast reply! This is my friends setup and not at his house currently. So I'll try it out tomorrow. Was going to build myself the same setup however looking more and more into it I might find myself getting the 2500k instead.