Jump to content

Welcome to Geeks to Go - Register now for FREE

Geeks To Go is a helpful hub, where thousands of volunteer geeks quickly serve friendly answers and support. Check out the forums and get free advice from the experts. Register now to gain access to all of our features, it's FREE and only takes one minute. Once registered and logged in, you will be able to create topics, post replies to existing threads, give reputation to your fellow members, get your own private messenger, post status updates, manage your profile and so much more.

Create Account How it Works

AMD CPU's 1066/800 limitation

  • Please log in to reply



    New Member

  • Member
  • Pip
  • 2 posts
Hello all, I'm new here as you can see.

I'll try to keep it short (which I always have trouble doing).

I'm building a gaming PC for my father and am not sure what kind of memory I should get. The PC's build can be found at the bottom of this post.

Here's the motherboard I chose - ASUS M4A78 Plus AM3/AM2+/AM2 AMD 770 ATX AMD Motherboard - Retail

Technical memory-related specs:
Number of Memory Slots 4Χ240pin
Memory Standard DDR2 1066*/800/667
* Due to AMD CPU limitation, DDR2 1066 is supported by AM2+/AM3 CPU for one DIMM per channel only.
Maximum Memory Supported 16GB
Channel Supported Dual Channel

So here's my dilemma. The CPU's integrated memory controller only supports one DIMM of 1066 per channel. What should I get? This machine is probably going to run Vista, or if possible be an XP/Vista dual-boot setup. I don't know too much about Vista, but I know it is a memory hog. I'm guessing I should get around 6 to 8gb of memory, but am not sure. How much memory should I have for gaming with Vista?

Also, I'm not clear about what a channel is. Let's say there are four DIMMs. Are DIMMS 1 and 2 a channel, or is it 1 and 3? (Question Answered from a friend)

I was looking at this memory - G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model F2-8500CL5D-4GBPK - Retail
If I bought 8GB of this memory, would all of the memory slow to 800, or would half of it be 1066? My assumption would be the former, in which case I'm not sure if I should get 4GB 1066 or have 8GB of 800. Unfortunately, I do not see any 4GB modules of 1066 RAM to do 2 x 4GB, although I have not thoroughly searched yet.

Is the increased bandwidth even worth it, or will it not make a difference for my build?
No point in going crazy if the bandwidth isn't going to be used,

Thanks in advance, and if you need any more info, please ask!

----------Other PC Components---------
• AMD Phenom II X4 3.0GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM2+ 125W Black Edition
• Memory???
• EVGA GeForce GTX 280 1GB 512-bit GDDR3 PCI Express 2.0 x16 SLI Supported Video Card
• ASUS M4A78 Plus 770 ATX Motherboard
• Western Digital Caviar SE16 320GB 7200 RPM 16MB Cache SATA 3.0Gb/s
• OCZ ModXStream Pro 700W ATX12V V2.2 / EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Modular Active Power Supply
• ATX Mid-Tower

Edited by NevNiv, 15 June 2009 - 07:47 PM.

  • 0




    Tech Staff

  • Technician
  • 16,645 posts
Hello NevNiv...

4 GB of 1066 RAM installed in a dual channel configuration should be more than adequate for all but the most extreme gaming. The channels on that motherboard are staggered, so the A channel will be slots 1 and 3...the B channel will be 2 and 4. Dual channel configuration is color coded...you'll want to install the RAM in the yellow slots (A1 and B1).

When RAM modules of different speeds are installed on the same board, they will always run at the speed of the slowest module, so stay with one speed and use dual channel. There have been issues with ASUS boards running at 1066MHz, so be sure to check the manual to see what settings are required to run at the higher speeds. If you decide to go with the slower modules and more than 6GB of RAM, you will probably have to bump up the RAM voltage a little to make it run. Running 8GB on my ASUS M3N-HT requires the voltage to be set to 2.23v rather than the 1.8v it's set to from the factory.

The RAM you've chosen is pretty good. I've also had very good luck with OCZ Reapers, though the modules are a little more money, they tend to run a little cooler with the oversized heat sinks they use.

Vista is not the memory hog people report it to be. It grabs a little less than half the installed amount and runs on that unless more is needed...which makes it look like a hog, but it uses the RAM very efficiently. When you open various programs, they run from the RAM Vista has already reserved, leaving the rest for more intense operations.

Another thing to remember is that 32 bit Windows will not utilize the full 4 GB of RAM. In order to use 4 GB or more, you'll need to install a 64 bit operating system.

Looks like a pretty nice build... :)

  • 0



    New Member

  • Topic Starter
  • Member
  • Pip
  • 2 posts
Awesome! Thanks for the informative answer. I may just order that RAM, it looks pretty funny, haha. I've never heard of G.skill anyway.

Thanks again! :)
  • 0

Similar Topics

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

As Featured On:

Microsoft Yahoo BBC MSN PC Magazine Washington Post HP