4 GB 1066 or 6 GB 800

[ripudaman]

Hi,

I have bought new ram G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel & prior to that I have 2 GB Kingston 800 FSB, now i have remove then & replace it with these, if I will then together then all ram will work on 800 FSB but the count will be 6 GB.... which config is better kindly suggest.

Thanks,
Ripu Daman

 

[compulsivebuilder]

Depends what's more important to you - size or speed

4GB is quite a bit, and if you are using a 32 bit operating system, it's all you can use (6GB is not very useful in a machine running a 32 bit OS). I'd lean towards using the 4GB.

 

[jerrya]

Hi,

I have bought new ram G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel & prior to that I have 2 GB Kingston 800 FSB, now i have remove then & replace it with these, if I will then together then all ram will work on 800 FSB but the count will be 6 GB.... which config is better kindly suggest.

Thanks,
Ripu Daman

From experience...

32bit Windows: Install 4GB and you will only see about 3.25. Thats as good as it gets.

64bit Windows: Anything above 4GB helps, 8GB is reasonable unless your are running Virtual Machines.
1. Size matters more than speed.
2. Windows limits for x64 Vista/7 Home 8GB, Home Premium 16GB, Business/Pro/Ultimate 128/192GB.
3. In real life I find it difficult to use more than 10GB.
4. Be aware that your pagefile should be at least equal to your memory size.

Jerry Adams

FYI: x64 Windows Server, SBS 2008, & SBS 2011 all want more than 8GB, 16 to 32 is reasonable.

 

[jaquith]

The differences in speed between DDR2 800 and 1066 is negligible 1-3%, and combined it would all have to run DDR2 800. Example -> http://images.anandtech.com/reviews/memory/ddr2/2006/patriot-1066/performance.html

The 'problem' is in mix-matching Frequency and CAS Timings; I assume the Voltages are identical otherwise forget it.

DDR2 800 4-4-4-12 @ 1.8v
DDR2 1066 5-5-5-15 @ 2.2v ; review the JEDEC 800 CAS Timings & Voltage per CPU-z
====================
DDR2 800 5-5-5-15 @ 2.0v ; and hope the Voltage disparity works

Worst, Mix-Matching tends to lead to excessive errors for the advantages are gone if that's the case.

IMO - run the 'G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066' by itself and obviously >4GB requires a 64-bit OS.

 

[ripudaman]

Hi,

The OS is Windows 7 64-bit (Ultimate)....my main concern was both set are the different voltage DDR2 800 at 1.8 & DDR2 1066 at 2.0 to 2.2 & I don't think that they will work together that well & is there a huge difference between 4 GB 1066 & 6 GB 800, other wise i will drop 2 GB(which is the current scenario).

Thanks,
Ripu Daman

 

[jaquith]

As I stated, "I assume the Voltages are identical otherwise forget it.

I also stated. "1066...review the JEDEC 800 CAS Timings & Voltage per CPU-z." If the DDR2 800 and 1066 @ 800 overlap {CAS & Voltage} then you 'should' be able to use them together. This requires you to boot with the 800 & 1066 separately and compare.

Good Luck!

 

[ripudaman]

Hi,

I have put both rams together..but i haven't change any setting...its automatic only..can i change some setting if there is any or just be glad that it worked. My mother board is Asus P5Q pro.

Thanks,
Ripu Daman

 

[jaquith]

Using the following as an example, use the highest CAS Timings of either set at the equivalent 'SPD'; in the case of DDR2 800 {400 MHz} look at the corresponding CAS Timings and Voltage of the DDR2 1066 {533 MHz}.

DDR2 800 4-4-4-12 @ 1.8v
DDR2 1066 5-5-5-15 @ 2.2v ; review the JEDEC 800 CAS Timings & Voltage per CPU-z
====================
DDR2 800 5-5-5-15 @ 2.0v ; and hope the Voltage disparity works

BIOS
DRAM Frequency -> 800 MHz
DRAM Timing Control -> Manual
CAS# Latency -> 5
DRAM RAS# to CAS# Delay -> 5
DRAM RAS# Precharge -> 5
DRAM RAS# Activate to Precharge Time -> 15
DRAM Voltage -> 2.0v

 

[ripudaman]

Hi,

The setting you suggested worked but I felt that my OS started reacting slower then before.... particularly for some applications like explorer, win-zip & few other applications & I did see much difference from 4 GB with 1066. Do let us know if I am wrong at some point & thanks for all the help.

Regards
Ripu Daman

 

[jaquith]

IF you are ***ONLY*** running "DDR2 1066 5-5-5-15 @ 2.2v" by themselves and ***WITHOUT*** DDR2 800 4-4-4-12 @ 1.8v then change the settings.

ONLY DDR2 1066 5-5-5-15 @ 2.2v:

BIOS
DRAM Frequency -> 1066 MHz
DRAM Timing Control -> Manual
CAS# Latency -> 5
DRAM RAS# to CAS# Delay -> 5
DRAM RAS# Precharge -> 5
DRAM RAS# Activate to Precharge Time -> 15
DRAM Voltage -> 2.2v