Bought P55 Ram for AM3 PC

If the memory chips are working fine then you won't be able to return them. If the chips are running fine at 1600mhz then i would not worry about the timings. the 1600mhz chips are faster then the 1333mhz chips.

Hello,

RAM timings can get to be very confusing

In checkout the specs link you gave for your computer, it states the "old" RAM is 801 MHz with timings of 9-9-9-21, not 7-7-7-21. RAM with a tCL of 7 is possible, but pretty fast. When you use "dual channel" DDR3 memory, the actual RAM speed is twice the stated speed, so your "old" RAM should be able to run at 1600 +-, at 9-9-9-21.

Your "new" RAM specs for the Patriot RAM are a Max of 1600 MHz with timimg of 9-9-9-24, not 9-9-9-21.

Most P55 MBs have a Base Clock Speed of 133 so 3 times that is 667, for a dual channel RAM speed default speed of 1333. And when you "overclock" it slightly to 4 times, the RAM clock speed is 800, dual channel is 1600.

Your "new" RAM probably couldn't handle the original tight timing. As a "general" rule, the last number should be the sum of the other three +- 1 or 2.

So after all that, it looks like the set of 4 are just fine, and both sets will handle uping the Controller speed to 800 ie 1600.

Consider setting the timing at 9-9-9-24 which will give the RAM 3 extra clock ticks to reset and will problably be more stable without losing any speed.

And yes, the 1600 MHz chips are faster than the 1333 default setting.

Hope that's helpful.

Hey thanks for the info, but i think you mis-read something, or I did. I bought the Patriot Sector 5 for my new system and thought they would automaticly set themselves to 1600mhz, but after looking at the bios they were at 1333 7-7-7-xx(I think 19 or 21) If i left them at all on auto they were unstable @ 1600mhz
but when i went into bios and set the timings myself @ 9-9-9-21 they were stable. I was wondering if this was safe/stable, and also is there anyway I could lower the timings to make them faster or what I can do to make them faster since this ram set was not made/"certified" for amd pc's in mind.

That memory kit was designed to run at 1600MHz with 9-9-9-24 timings at 1.65v. You probably won't be able to get lower timings unless you down-clock the RAM to 1333MHz again. That would slow your system down.

By the way, memory isn't actually designed for AMD or Intel only. It doesn't care what system it's installed in. The "designed for Core i7" or whatever is just marketing.

Ahh okay thanks for clearing that up

Hello again,

Use your RAM at 1600 MHz, timing at 9-9-9-24. The timing number that really makes a difference is the first one, the tCL or CAS as it is called. The CAS at 7 didn't work, and most likely trying it as 8-8-8-24 will cause to drop the speed back to 1333 Mhz. The 1600 Mhz will be faster.

Of note, the speed and timing on RAM is the Max it has been checked (certified) to run reliably by the manufacturer. It's not, as you noted initially, what the MB Memory controller is set by default. 1333 Mhz is pretty much the default standard for most recent MB's. It is also not the Max overclocking speed you may get out of the RAM, as serious overclockers may push their RAM speed up even further as they increase their CPU speed.

For what it's worth, a recent answer in Max PC Magazine about what the optimal RAM frequency put it at 1333 Mhz
Your present setting is fine, wouldn't worry about it.