2GB or 4GB of RAM for Vista?

[bomax]

I'm finally putting together my first C2D build with Vista. For the past few years or so I've been sticking with just two sticks of RAM because it was always better to have fewer sticks. I also like to stick with lower latency memory. Now that Vista is out, I'm hearing rumors that 4GB is the sweet spot. There are very few 2GB memory modules available, and they're all CAS 5.

The question: Is it better to have 2 x 2GB CL5, or 4 x 1GB CL4 memory? Or, should I just stick with 2GB of memory?

Thanks!

 

[crossrode]

Originally posted by: bomax
I'm finally putting together my first C2D build with Vista. For the past few years or so I've been sticking with just two sticks of RAM because it was always better to have fewer sticks. I also like to stick with lower latency memory. Now that Vista is out, I'm hearing rumors that 4GB is the sweet spot. There are very few 2GB memory modules available, and they're all CAS 5.

The question: Is it better to have 2 x 2GB CL5, or 4 x 1GB CL4 memory? Or, should I just stick with 2GB of memory?

Thanks!

We then upgraded the Vista machine to 3GB and ran the test again; thanks to faster application load times and intelligent prefetching, Word started in 1.31 seconds. If you thought that 2GB was the sweet spot for Windows XP, chances are 3GB will be the new minimum for you under Vista.

Read on:

RAM and Vista

 

[bomax]

I've read the article, but was wondering if anyone here has first hand experience. Plus 3GB seems so.... uneven.

 

[crossrode]

Originally posted by: bomax
I've read the article, but was wondering if anyone here has first hand experience. Plus 3GB seems so.... uneven.

I use 3GB with Vista 32 and ASUS P5B-DEluxe, e6600. 3GB is noticably faster than 2 in my system.

 

[bomax]

Vista 32 can run 4GB though, right? I know it can not run "more" than 4GB, but 4GB is ok right?

 

[crossrode]

Originally posted by: bomax
Vista 32 can run 4GB though, right? I know it can not run "more" than 4GB, but 4GB is ok right?

You will need Vista 64 to have the OS allocate and utalize 4GB RAM properly. Three GB works much better than two in Vista 32.

 

[BlingBlingArsch]

make it 8.

 

[crossrode]

I think OP will find 4GB will work much better than 2GB. That is the question he is posing.

 

[atchon]

You will need Vista 64 to have it fully see the 4GB otherwise you will get a cut down number depending on the other hardware. Such as you may get 3.2 - 3.5 GB actually registering. IIRC its because the bus is shared between other hardware as well so how much of the 4GB you see will depend on what else is taking up bus space.

 

[Imyourzero]

The thing that sucks about 3GB is that you forfeit dual channel mode. But I guess with Vista the performance gain from that extra gig of RAM overshadows the comparatively minor loss from not having all of your memory running in DC mode.

 

[bomax]

Originally posted by: atchon
You will need Vista 64 to have it fully see the 4GB otherwise you will get a cut down number depending on the other hardware. Such as you may get 3.2 - 3.5 GB actually registering. IIRC its because the bus is shared between other hardware as well so how much of the 4GB you see will depend on what else is taking up bus space.

I've been doing some research and you are absolutely correct. However, I can alternately enabled the /PAE switch within Vista 32 and it will allow me to utilize the full 4GB. What I'm researching now is whether this will cause a performance degradation. From what I've been able to find out so far, it will not.

 

[bomax]

Originally posted by: Imyourzero
The thing that sucks about 3GB is that you forfeit dual channel mode. But I guess with Vista the performance gain from that extra gig of RAM overshadows the comparatively minor loss from not having all of your memory running in DC mode.

Wow this is an EXCELLENT point! I'm surprised I didn't think of that before. With 4 sticks of RAM, is dual channel still enabled?

 

[crossrode]

Originally posted by: Imyourzero
The thing that sucks about 3GB is that you forfeit dual channel mode. But I guess with Vista the performance gain from that extra gig of RAM overshadows the comparatively minor loss from not having all of your memory running in DC mode.

Dual channel runs fine with 4 DIMMS occupied on my C2D system. I have 2 x 1GB in channel 1 and 2 x 512 in Channel 2. All matching G. Skill PC6400 CL4.

 

[Synomenon]

Yes, you'll still have dual channel mode with 3GB of RAM as long as you match two 512MB sticks in the same color slots and two 1GB sticks in the other color slots. As long as matching sticks are in matching color slots, you'll have dual channel.

 

[crossrode]

Originally posted by: bomax

Originally posted by: Imyourzero
The thing that sucks about 3GB is that you forfeit dual channel mode. But I guess with Vista the performance gain from that extra gig of RAM overshadows the comparatively minor loss from not having all of your memory running in DC mode.

Wow this is an EXCELLENT point! I'm surprised I didn't think of that before. With 4 sticks of RAM, is dual channel still enabled?

I have been runing this system for months. Your C2D system will run dual channel with 4 matching DIMMS on any 965, 975 or 680 chipset MB. Should you mix and match the 4 DIMMS with various latency timings, I'm not completely sure. Mixing the CAS latency timings with 4 DIMMS on some AMD Nforce 4 systems will nullify dual channel. I don't know if that holds true with the latest Intel chipsets. You have nothing to worry about if you buy 4 matching DIMMS. You will be able to run in dual chaneel.

e6600 C2D
ASUS P5B-Deluxe
G. Skill PC6400 (3 GB) 2 x 1 GB + 2 x 512 MB on Vista Home Premium 32
Corsiar Turbo flash 1 GB for Vista Readyboost
EVGA 7900 GTO
Dual Boot with XP Pro 74 GB SATA Raptor + 2 x 250 GB WD SATA
Thermaltake Mozart tower
LED Remote Control Panel
ASUS Lightscribe DVD-R
Eleven LED 120 mm fans
Thermaltake 700 watt PSU
Zalman 9500 LED

 

[bomax]

Thanks guys for clearing that up

 

[crossrode]

Originally posted by: bomax
I'm finally putting together my first C2D build with Vista. For the past few years or so I've been sticking with just two sticks of RAM because it was always better to have fewer sticks. I also like to stick with lower latency memory. Now that Vista is out, I'm hearing rumors that 4GB is the sweet spot. There are very few 2GB memory modules available, and they're all CAS 5.

The question: Is it better to have 2 x 2GB CL5, or 4 x 1GB CL4 memory? Or, should I just stick with 2GB of memory?

Thanks!

I was reading this forum the other day. See if reading this thread helps answer your question:

So with 4GB of physical RAM installed, with addresses going from 0 to 4GB, I am robbed of the use of the top 1088 MB of RAM and am left with 4096-1088=3008 MB of usable RAM when the Memory Remap Feature is not enabled. When it is, 2GB of RAM are given the addresses 0-2GB, and 2GB reside at 4-6GB, while Windows uses his 1088MB between address 3008MB and 4096MB for devices and God knows what it does with the remaing 2048-1088=960MB address range between 2GB and 3008MB. In any case, the hardware gets the same addresses in both cases, in the 3008-4096MB range.


Long read concerning Vista allocating RAM

 

[bomax]

Ok... after several hours of reading, I have come to understand the issues here fairly well. From this point forward I assume other people understand as well, so I won't bother paraphrasing.

Since my video card is 512MB, I'm afraid that's really going to eat into the 4GB address space I have to work with. And since PAE is unreliable at this time, I am leaning towards the 3GB that crossrode an Anandtech are recommending. 2x1GB and 2x512MB.

I think this subject would be worthy of a dedicated article on Anandtech, as the issue is only going to come up more and more as RAM prices fall.

Please continue to post useful links as you come across them.

 

[crossrode]

Hey PM me when Quad Core processors drop below 3 bills! 8) Yeah, my systems runs really nice with 3GB PC6400. The readyboost feature is great too. See Anandtech article 'readyboost'. GL with your C2D system. Nice!

 

[imported_AndyT]

Use some caution here!

There are some boards out there that won't boot at all with mis-matched memory. Some of the DFI boards are known for this. Even memory from the same manufacturer can cause this problem. Mixing kits sizes and chip types can cause these boards to plain refuse to boot at all, ever. The only real way to know is to try the mmeory in the board.

 

[Imyourzero]

Originally posted by: bomax
Thanks guys for clearing that up

Yep, what crossrode said is correct. You'll be fine running dual channel with 2x1GB and 2x512MB...for some reason I was thinking you were planning to upgrade to 3GB by adding a single 1GB module (d'oh). I shouldn't have said 3GB makes you forfeit dual channel mode, I should have said that 3x1GB sticks obviously won't be able to run in DC mode.

My question: what affects performance the least, losing dual channel mode or having to reduce timings when populating all 4 DIMM slots?

 

[imported_AndyT]

Originally posted by: Imyourzero

Originally posted by: bomax
Thanks guys for clearing that up

Yep, what crossrode said is correct. You'll be fine running dual channel with 2x1GB and 2x512MB...for some reason I was thinking you were planning to upgrade to 3GB by adding a single 1GB module (d'oh). I shouldn't have said 3GB makes you forfeit dual channel mode, I should have said that 3x1GB sticks obviously won't be able to run in DC mode.

My question: what affects performance the least, losing dual channel mode or having to reduce timings when populating all 4 DIMM slots?

Both situations probably won't creat a noticeable performance hit unless you are benchmarking.

My concern is more troubling as mixing memory types can lead to stability issues or may not run at all. Been there, done that, had that frustration (and tried to help hundreds of customers with this problem). Just make sure you have a plan B (return new memory, sell old memory....) just in case.

 

[crossrode]

Originally posted by: AndyT

Originally posted by: Imyourzero

Originally posted by: bomax
Thanks guys for clearing that up

Yep, what crossrode said is correct. You'll be fine running dual channel with 2x1GB and 2x512MB...for some reason I was thinking you were planning to upgrade to 3GB by adding a single 1GB module (d'oh). I shouldn't have said 3GB makes you forfeit dual channel mode, I should have said that 3x1GB sticks obviously won't be able to run in DC mode.

My question: what affects performance the least, losing dual channel mode or having to reduce timings when populating all 4 DIMM slots?

Both situations probably won't creat a noticeable performance hit unless you are benchmarking.

My concern is more troubling as mixing memory types can lead to stability issues or may not run at all. Been there, done that, had that frustration (and tried to help hundreds of customers with this problem). Just make sure you have a plan B (return new memory, sell old memory....) just in case.

My experience has been AMD NForce 4 MB's are very sensitive to mix and matching DIMMS with non-matching CAS LATENCYS. Like 2 x 1GB OCZ Platinum PC3200 CAS 2 in channel 1 and combining with 2 x 512 MB Kingston PC3200 CAS 3 in channel 2. Even by setting the RAM timings in BIOS on a Gigabute Nf4 SLI board, the system I built a week ago would NOT run in dual channel with this set up. On my ASUS P5B-Deluxe 965 I run 2 x 1 GB in channel 1 and 2 x 512 MB in channel 2 all the exact G. Skill PC6400 4-4-4-12 with no problems. Runs at 1T overclocked without issue. Unlike my Intel 965 chipset, The AMD NF4 demands 2T when you use 4 DIMMS.

 

[otispunkmeyer]

Originally posted by: Imyourzero
The thing that sucks about 3GB is that you forfeit dual channel mode. But I guess with Vista the performance gain from that extra gig of RAM overshadows the comparatively minor loss from not having all of your memory running in DC mode.

2x1Gb

+

2x512

= 3gb

all dimms full

dual channel still a go

 

[otispunkmeyer]

Originally posted by: crossrode

Originally posted by: bomax

Originally posted by: Imyourzero
The thing that sucks about 3GB is that you forfeit dual channel mode. But I guess with Vista the performance gain from that extra gig of RAM overshadows the comparatively minor loss from not having all of your memory running in DC mode.

Wow this is an EXCELLENT point! I'm surprised I didn't think of that before. With 4 sticks of RAM, is dual channel still enabled?

I have been runing this system for months. Your C2D system will run dual channel with 4 matching DIMMS on any 965, 975 or 680 chipset MB. Should you mix and match the 4 DIMMS with various latency timings, I'm not completely sure. Mixing the CAS latency timings with 4 DIMMS on some AMD Nforce 4 systems will nullify dual channel. I don't know if that holds true with the latest Intel chipsets. You have nothing to worry about if you buy 4 matching DIMMS. You will be able to run in dual chaneel.

e6600 C2D
ASUS P5B-Deluxe
G. Skill PC6400 (3 GB) 2 x 1 GB + 2 x 512 MB on Vista Home Premium 32
Corsiar Turbo flash 1 GB for Vista Readyboost
EVGA 7900 GTO
Dual Boot with XP Pro 74 GB SATA Raptor + 2 x 250 GB WD SATA
Thermaltake Mozart tower
LED Remote Control Panel
ASUS Lightscribe DVD-R
Eleven LED 120 mm fans
Thermaltake 700 watt PSU
Zalman 9500 LED

i thought when you start mixing an matching, so long as size is the same, timings will be adjusted to the lowest common denomitator. if not its hardly a chore to adjust the timings by hand.