2009/10/01 09:06:04
rjohnson11
(Originally posted by BabyBalla)
 
Memory Ram Explained

What is it?
RAM or Random access memory is a location where codes are being loaded and departures any time when you execute a program. For an example when you load firefox everything you need is loaded into the ram. For it to operate. When you exit the program it leave the ram making room for you next program. Having more ram is an good advantage for those people who do a lot or some multi tasking.

What is the different between SDRAM, DDR, DDR2, DDR3/GDDR3/GDDR4/GDDR5/

Speed.

SDRAM is the slowest out of all the ones listed above. Compare to DRAM its still slower but what is the different between the two was the mass bandwidth SDRAM created which made it very popular
DDR/DDR2/DDR3 is a upgrade version of SDRAM DDR introduced Double write cycle, SDRAM write and reads one bit at a time while DDR writes 2 and reads 2 bits at a time, DDR2 writes and reads 4 bits, DDR3 writes and reads 8bits This technology increases bandwidth on the ram dynamically.
GDDR3/GDDR4/GDDR5 Is ment for video cards, These run on the same concept as DDR


How to I know enough is enough?
It depends on what you do. Here my chart on what i think enough is enough, you may disagreed.



What about ram speeds?

Faster the ram, means its has much more bandwidth, more bandwidth allows more information to get to the CPU, Having a fast CPU but slow ram causes a Bottleneck. Which is a fancy word for a traffic jam.

Timing

  • RAS - Row Address Strobe or Row Address Select
     
  • CAS - Column Address Strobe or Column Address Select
              -It controls the amount of time in cycles between sending a reading command and the time to act on it. From the beginning of the CAS to the end of the CAS is the latency. The lower the time of these in cycles, the higher the memory  performance.
  • tRAS - Active to precharge delay; this is the delay between the precharge and activation of a row
               - The amount of time between a row being activated by precharge and deactivated. A row cannot be deactivated until tRAS has completed. The lower this is, the faster the performance, but if it is set too low, it can cause data corruption by deactivating the row too soon.
  • tRCD - RAS to CAS Delay; the time required between RAS and CAS access
               - Is the amount of time in cycles for issuing an active command and the read/write commands.
  • tCL - (or CL) CAS Latency
  • tRP - RAS Precharge; the time required to switch from one row to the next row, for example, switch internal memory banks
             -This is the minimum time between active commands and the read/writes of the next bank on the memory module.
  • tCLK – ClocK; the length of a clock cycle
  • Command Rate - the delay between Chip Select (CS), or when an IC is selected and the time commands can be issued to the IC
  • Latency - The time from when a request is made to when it is answered; the total time required before data can be written to or read from the memory

Tighter timing will led to more bandwidth This will help from you computer speeds as far as launching programs and a bit when running them. A person who does a lot of Video editing/gamer/multi-tasker may want to consider Fast and tight timing ram, While the Average user may just want to save the some money and buy slower and looser ram.





< Message edited by BabyBalla -- 7/18/2009 2:14:01 PM >

2009/11/13 21:12:46
rlynn23
Nice post with lot's of good info!Thank you R.J.!
2009/12/07 15:18:06
babyballa
rlynn23

Nice post with lot's of good info!Thank you R.J.!



why thank you :) I need to update this thread. Since the Core i7 are out. 
2010/02/08 15:06:10
jliles01
rjohnson, babyballa (I'm confused)

I'm getting a      404 NOT FOUND   with the link to the chart link above.
2010/04/14 18:05:00
babyballa
2010/06/01 20:54:18
kylesundell
great info
2010/06/12 11:30:26
rlynn23
babyballa

rlynn23

Nice post with lot's of good info!Thank you R.J.!



why thank you :) I need to update this thread. Since the Core i7 are out. 

Thank you because this was good info for many people and I do not own an i7 so for now the i7 info is not too important.
2010/06/24 14:05:47
brad22582
thanks, you put it in a way that's very easy to understand...

really looking forward to using the marketplace
2010/12/14 19:22:19
docta_tucka
helpful in a couple places.  any plan on when the i7 guide will be put up? (no rush, just curious)
2011/08/09 14:54:11
shinra_
good info

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