|  | | FSX a RAM 28. 9. 2013 / 00:02 | |
| | SYSTEM MEMORY
One of the most overlooked and underrated aspects of system building is proper memory speed and timing. Regardless of the nonsense you may read about memory specifications and games (or FSX) DO NOT skimp on this area! Physical memory timing and speed quality does not effect FPS 'greatly' but firmly improves scenery loading and visual flight smoothness.
FSX does not need more than 6GB - 8GB of physical memory! Be aware, adding more memory is not going to net you any better performance and if you do add more you may find that memory will run higher latency or could be unstable in a high CPU clock situation. Users who may need more memory than 8GB for engineering or A/V production work or 64bit applications, that is understandable but anyone who does not use their systems for much more than FSX would be foolish to purchase more than 8GB. Your version of Windows must support the amount of memory you intend to use as well. Windows 7 Home x64 is restricted to 8GB max.
TWO STICKS vs. FOUR: What you must understand about this is that when we use more that 2 sticks of memory the load on the CPU memory controller or IMC goes UP. Therefore what users may deal with is LOWER stability in a HIGHER CPU clock with HIGHER speed memory. Typically you wont have any issues running 4 sticks when clocking 4.3 or below, above that it can become problematical as CPU speed and memory speed increases. How much depends on the motherboard quality and the luck of the draw with the CPU.
Users who run quad channel memory CPUs will be running 4 sticks of memory. That does not mean its bad as they get the benefit of the quad memory channel operation, however users who do not run quad channel CPUs that do not require more than 2 memory slots populated should strive to run 2 sticks for maximum stability in clocking. Unless you need more memory for applications that will make use of it, in that case you will have to deal with any issues running higher CPU clock speeds.
Just as some CPUs display the ability to run high clocks on low CPU voltage, the same holds true with their stability with more than 2 sticks running at very high CPU and memory speeds.
HOW TO GET THE BEST BANG FOR THE BUCK OUT OF THE MEMORY SELECTION:
I know to some people this information may appear 'Greek' however follow this chart with the examples I show, and you cant go wrong.
SAMPLES OF MEMORY SPEED/TIMING
Memory is specified in speed and timing. The first number, in example is DDR3 the values that follow are the timing values listed as:
DDR3 CAS Latency - RAS to CAS DELAY - RAS Precharge - Cycle Time
Example: DDR3 2133 C9 -11-10-28
The first value, CAS Latency, has the highest influence on performance. The lower, the faster.
The 2nd and 3rd numbers also influence the speed of the memory and this is where a lot of people get snookered by a memory company into thinking the memory they are purchasing is faster than a lower speed.
In example: DDR2 1600 6-7-6-18 is FAR FASTER than DDR3 1866 9-9-9-24
Memory companies know people look at the speed of the memory instead of the timing and to take this example a step further lets try this again:
DDR3 2133 9-11-10-28 is FASTER than DDR3 2133 9-12-12-28
Even though both are the same DDR speed and both are CAS9 rated, the two numbers - RAS to CAS DELAY and RAS Precharge are higher in the 2nd sample and therefore that memory is slower and it could even be priced higher than the other sticks!
Cycle Time (the last number) does have an influence on the overall memory speed and it is always best to go for a lower value, however Cycle Time is not as critical to memory performance as are the other values therefore I have not included the Cycle Time value in the list below.
Here is a list of memory timing per speed a user should strive for. Lower timing memory is typically expensive and hard to find, which is what you pay for.
DDR3 SPEED - HOLY-GRAIL TIMING - (EXCELLENT TIMING you should buy)
DDR3 1333 - 5-5-5 - (6-6-6)
DDR3 1600 - 6-6-6 - (6-8-6 best or 7-8-7)
DDR3 1800/1866 - 6-8-6 - (7-8-7)
DDR3 2000 - 7-7-7 - (8-8-8) Intel 900/970/980 series 'stable' limit
DDR3 2133 - 8-8-8 - (9-10-11) Sandy Bridge 'stable' limit, can go slightly higher
DDR3 2400 - 9-9-9 (9-11-11) Ivy Bridge and Haswell 'stable' limit, SB-E 'may' run this too but not very easy.
DDR3 2800 - 10-10-10 (11-14-14) Haswell can run this, can go higher but you are now into 'tech experience' level speeds and not suggested
DDR3 3000 - 11-11-11 (12-14-14)
Any of the processors will run the lower memory speeds of 1600-1866 but if your processor is able to run stable at higher speed, always shoot for that stable speed limit with the timing. |
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