Vista Ultimate x64 & 4GB RAM

[Clocker]

I decided to install Vista x64 on a separate HDD for a 30-day trial just to play with it. I was suprised to see that, even though I have 4GB RAM, my lowest score on Sytem Information tool was related to ram:

Performance Information and Tools
Processor
AMD Athlon(tm) 64 X2 Dual Core Processor 4400+......................SCORE 4.9/5.9
Memory (RAM) 4.00 GB..........................................................SCORE 3.8/5.9
Radeon X1900 Series............................................................SCORE 5.9/5.9
Gaming graphics 2303 MB Total available graphics memory...........SCORE 5.8/5.9
Primary hard disk 138GB Free (153GB Total)..............................SCORE 5.2/5.9

 

[ddrueding]

I don't think it's the amount of RAM at that point, it's more likely the speed. What is the spec on the RAM?

 

[Clocker]

It's OCZ CAS2 (2-3-2-5) Platinum DDR400 stuff.

 

[Clocker]

Here's something odd from CPU-Z:

Chipset & Memory
Northbridge ATI Xpress 3200 (RD580) rev. 00
Southbridge ALI M1575 rev. 00
Graphic Interface PCI-Express
PCI-E Link Width x16
PCI-E Max Link Width x16
Memory Type DDR
Memory Size 4096 MBytes
Memory Frequency 100.2 MHz (CPU/22)
CAS# Latency (tCL) 2.5 clocks
RAS# to CAS# (tRDC) 2 clocks
RAS# Precharge (tRP) 2 clocks
Cycle Time (tRAS) 5 clocks
Bank Cycle Time (tRC) 7 clocks
DRAM Idle Timer 16 clocks
Command Rate 2T

I wonder if having all 4 DIMM slots populated has made my system slow down to 100Mhz DDR ram? I manually set the memory speed to 200Mhz in the BIOS but it doesn't seem to be making a difference. I'll pull some ram to see if it makes a difference.

 

[Clocker]

Reducing RAM to 3x1GB=3GB lowered my score to somewhere in the 2's...it was still running at 100Mhz.

Reducing RAM to 2x1GB=2GB INCREASED my score to 5.1/5.9 from 3.8/5.9 with 4x1GB=4GB because the RAM is now running at 200Mhz.

I knew there were some problems with the earlier A64's and larger amounts of RAM where the speed was reduced but I didn't know the Toldeo core X2s had the same issue.

Anybody share the same experience? Do the C2Ds have this issue?

Thanks,
C

 

[ddrueding]

My system is currently running 4x1GB DDR2 800 @ 800Mhz...but that is DDR2 on an AM2 board. I don't think there were any issues on these.

 

[Clocker]

Crapola. Maybe it is time to experiment with C2D.

 

[ddrueding]

Crapola. Maybe it is time to experiment with C2D.

I'm about to post a system spec that may interest you.

 

[Bozo]

On Intel motherboards, the memory needs to be matched pairs installed in the proper slots for best performance. Dual Channel mode.
Is this the same on AMD motherboards?

Bozo :joker:

 

[ddrueding]

yep.

 

[Chewy509]

I wonder if having all 4 DIMM slots populated has made my system slow down to 100Mhz DDR ram? I manually set the memory speed to 200Mhz in the BIOS but it doesn't seem to be making a difference. I'll pull some ram to see if it makes a difference.

Dual rank or Single rank RAM? Depending on the revision, you may be limited to 6 ranks total to obtain DDR400, otherwise if more than 6 ranks are installed, then the BIOS should downclock your RAM to DDR333. (Some BIOSs will downclock to DDR333 even if you just have 4 sticks of RAM irrespective if it's dual or single rank as per an early revision of the AMD BIOS writers guide).

In the Opteron line, the following is a rough guide:
Stepping Ax to Bx - 2 or 4 sticks - DDR333 (max 6 ranks)
Stepping Cx - 2 sticks DDR400, 4 sticks DDR333 (max 6 ranks)
Stepping Dx to Ex - 2 or 4 sticks DDR400 (max 6 ranks), 6+ ranks then DDR333.
Some Ex's allow DDR400 with more than 6 ranks (nothing official)

I would assume something very similar with the other AMD64 chips, since they share a common memory controller design.

Clocker, to be honest I don't think the CPU is an issue, more likely the BIOS is following an out-dated design guideline.

 

[Clocker]

I think I'm just going to sell 2GB and forget about it...

 

[Bozo]

Rank??

Bozo :joker:

 

[Clocker]

A double sided dimm has two 'Ranks'. I've seen it mentioned in other forums that way so I guess it is the term for a 'side' of memory.

 

[MaxBurn]

Yes, I ran into the speed problem and you can search some of my posts from last year with the 64 3700+ and the Asrock 939SLI32 and another Gigabyte board. Basically if you populate all four banks of memory it will bump the speed down and if you force it up it will be unstable. My solution was to buy 2x1gig instead of the 4x512.

I put the 4x512 into my Supermicro P4SCT with a P4C at 3.0 and it had no problem running them full speed.