2 Gb Ram + 512 Mb Ram

[smartygoldenfish]

i have a compaq presario pc core 2 duo windows xp+ubuntu

it had 512 mb ddr2 ram in one slot
i installed a 2gb ram ddr2 in another slot
there are 2 slots (now both filled)



also according to HP:

my ram has following characteristics
* Dual channel memory architecture
* Two 240-pin DDR2 DIMM sockets
* Supported DIMM types:
o PC2-3200 (400 MHz)
o PC2-4200 (533 MHz)
o PC2-5300 (667 MHz, runs at 533 MHz)
* Non-ECC memory only, unbuffered
* supports 1 GB DDR2 DIMMs
* Supports up to 2 GB


u can see my pc configuration at official hp site.

HOW COME WINDOWS XP SHOW THAT I HAVE 2.49 GB RAM WHILE MY PC SUPPORTS ONLY 2 GB!
AND ITS CLEARLY WRITTEN THAT MY PC SUPPORTS " 1 GB DDR2 DIMMS " DOES THAT MEAN I CANT HAVE 2 GB IN ONE SLOT! IS IT POSSIBLE THAT THOUGH MY PC IS SHOWING THIS 2.49 GB OF RAM, IT CAN ACTUALLY USE ONLY 1.49 GB RAM OR EVEN ONLY 512 MB RAM! :blink:

ALSO:
now my friends say since both rams are unequal 512 mb ram will slow down my 2 gb ram and i will not hav full performance.
i argue that 2 gb + 512 mb should give better performance then 2 gb + 0 mb
WHO IS RIGHT MY FRIENDS OR ME?


PLZ HELP

[saqib_khan]

OK, so u mean , in Properties of My Computer it is showing 2.49 GB RAM.

Also, use CPU-Z one time & see what amt of RAM it shows. And i think they have a typo mistake in the website regarding "* supports 1 GB DDR2 DIMMs".

If it is showing 2.49 GB RAM, then no problem, but also check one time with CPU-z.

Enjoy.

[RexRazr]

I think 2GB+512MB should give u better performance than 2GB+0 as it's not a matter of dual channel mode...only matter of memory amount
check the correct thing in CPUz as khansaqib101 said...
and...however...u can run some benchmarks with 2GB+512MB installed and then the same ones with just 2GB and see the difference

[Beta Waves]

Its obvious you have 2GB in one slot and 512MB in another slot. So totaling upto 2.5GB. So your system properties is showing 2.49GB.

* supports 1 GB DDR2 DIMMs
* Supports up to 2 GB

In the sense your RAM Slots supports both 1GB and dual density 2GB Stick.

If you want to utilize dual channel. you should have two equal size RAM sticks and equal Data transfer rate (i.e. Frequency)

[smartygoldenfish]

Originally Posted by Beta Waves

If you want to utilize dual channel. you should have two equal size RAM sticks and equal Data transfer rate (i.e. Frequency)

Is that really so?
see compaq is a big company and hence my computer should have come with 256*2 MB ram's instead of one 512 mb bcoz your post suggests that this will give better performance!
i think 1gb*2 OR 2gb*1 should give equal performance, because of my initial configuration of 512mb*1 by compaq.

what do u think?
also both my ram's NOW are 667 mhz

[RexRazr]

as ur mobo's RAM slots have dual channel architecture...then if u put two 1GB sticks (of same speed) occupying both channels...then they'll run in dual channel mode...while one 2GB stick in one slot will run in single channel mode...the former one (1GB*2) should give u much better performance

[Beta Waves]

Originally Posted by smartygoldenfish

Is that really so?
see compaq is a big company and hence my computer should have come with 256*2 MB ram's instead of one 512 mb bcoz your post suggests that this will give better performance!
i think 1gb*2 OR 2gb*1 should give equal performance, because of my initial configuration of 512mb*1 by compaq.

what do u think?
also both my ram's NOW are 667 mhz

See RAM buswidth is 64bits i.e 64 lines from RAM to your CPU .. So if you say your RAM frequency in 667Mhz. that means the number data transfer in one second will be 64X667X10^6 ..
If you have two RAM modules of 667MHz the effective transfer rate will be
2X64X667X10^6 which is double and obviously better... So in mobo with Dual channel availability it is better to have 1gb*2 rather than 2gb*1...