Ram timings

sellsword2002

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I've reading reviews on ram on tom's and on online retailers and keep seeing timing come up. Tight timing, quick timing etc. I read the FAQ on the memory board looking for some info but it really didn't clear it up for me.
What does the timing for ram mean and how does it affect performance?
 

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Illustrious


Did you read any mention of 'response time' or menton of how the response time of data held in memory waiting to be processed can be effected or even adjusted.
 

sellsword2002

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Q: How does memory access work, and what do the timings stand for?
A:
MEMORY ACCESS:
1. tRCD (RAS to CAS Delay) 2-3 cycles, The row is selected by the Memory Controller.
2. CAS (Column Address Strobe) 2,2.5,3 cycles (DDR), The Memory Controller selects the column and now the ROW is
ACTIVE, and the READ COMMAND is sent.
3. Data is sent to the DQ pins after CAS delay.
4. tRAS (Row address Strobe) 6 cycles, The module waits a certain period of time for the data to be active.
5. tRP (RAS precharge) 2 cycles, The Memory Controller DEACTIVATES the row.
6. Memory Cycle repeats as requested by the Memory Controller.

The timings are represented as follows:
2-3-2-6 1T (CAS, tRCD, tRP, tRAS)

The 1T is the command rate (see key term: command rate)
Is what is in the FAQ for timing

Command Rate (CMD): The command rate specifies how many consecutive clock cycles need to be sent to the memory modules before the modules can send data. Because wires often have natural capacitance on them, sometimes it takes longer for a wire to transition from a 1 to a 0. The CMD setting is typically one or two clocks and can often be adjusted between the two. It's represented as 1T or 2T.
And for command rate.
 

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Illustrious
So, I'm assuming this is all new information to you? It's a pretty good explanation. I tried to make my response simple, I was referring to latency misreading your post. That explanation of RAM timings is pretty good and about as simple as you will find.

""What does the timing for ram mean and how does it affect performance?"

A little more specific than this perhaps.
 

sellsword2002

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Yes, this would be new information. I haven't been looking at computer hardware for about 10 years because i didn't really have the money to buy some new hardware. Now I was looking at building a new computer and this term was coming up. I guess what i was looking for was will ram with a timing of say 8-8-8-24 give better performance than say some with a timing of 9-9-9-24.
I'll go hit up the interweb for more info about how ram works and what the previous explanation means.
 

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Illustrious
Generally, the lower the timings and with the least amount of voltage required to run those timings, the better the performance potential. If extreme OCing is involved, then the higher the capable speed, or data transfer rate, would come in to play. This also depends on what platform you are using and how the RAM controller works within the data transfer process.
 

sellsword2002

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Thanks for the info. So when looking at RAM at an online retailer, the Timing numbers being given refer to what the manufacturer are stating the timings should be set at for optimal stability?
I'm guessing in the big scheme of things, as long as the timing is set correctly there really isn't much difference when it comes to timing.
 

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Illustrious
The manufacturer is guaaranteeing the RAM will run at their advertised speed, voltage and timings. Depending on the MB and BIOS, RAM speed, timings and voltage are adjustable in BIOS. See MB manual under BIOS/RAM.
 

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