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two channels of dual-channel

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Pirate_Freder

Member
Joined
Aug 2, 2005
Location
Oregon
so i need to get ram that can do a really high fsb (>300) so i can do a 1:1 divider, unfortunately though, i cannot find ddr600 in sticks larger than 512mb. With the way games are going 2gb is pretty much required for good gaming performance. I have heard that you can run two channels of dual-channel from the IT guy at my school(gotta be true coming from him :p), is this true, if so, what mobos support it? does the DFI Lanparty SLI-DR?
 
Pretty much all boards today support 4x DIMMs. In essence they are 2x sets of Dual Channels. You can install 4x 512MB sticks, but it may limit your OC. You may not be able to get 300HTT.

And yes, that board has 4x dimm slots. but you will be limited to 2T.
 
Well, you get two channels with two sticks of RAM, but I'm guessing you mean using 4 sticks with 2 sticks per channel. The issue here isn't the mobo, it's the memory controller on the A64. You'll be looking at maybe a 3% performance hit for going to 2t, which you will have to do with the current chips. Also, you might see slightly lower overclocks, and some speculate that running four hot sticks of RAM might stress out the mobo. I'm not so sure about that last one, but it is something to consider.

Now, if you're used to the Barton in your sig, there's good news. With the A64's onboard memory controller, there is no latency penalty for using a memory divider. The RAM has it's own bus separate from the CPU, so you can run asynchronously without bogging down.

Also, the controller works so well that fast RAM doesn't boost your overal performance that much. Memory just isn't a major bottleneck. You might want to save some money on RAM and get a faster GPU or CPU.

http://forums.anandtech.com/messageview.aspx?catid=28&threadid=1475190&enterthread=y
 
oh well this is for my new system i'm building on the s939 platform with a 146 opteron, so i will be on the a64. so your saying that i won't be lagged up by having say ddr400 and a fsb clock of 325 on the cpu?
 
Yep, that's what I'm saying. It will make some difference, but probably a lot less than you've been thinking. Of course you would get a slight boost with faster RAM, but if you've got a budget, you might do better to get cheap to mid-range memory and put your bucks where they'll get you more bang. Read that Anandtech thread I linked above. It will change the way you think about RAM.

BTW, the hit for 2T more or less equals the hit for using 1GB modules that won't OC to the stars.
 
Otter is correct. There is no reason to worry about 1:1 with an A64. However, if you do want to go for high clocking 2x1gig DC ram the Ballistix are the highest clocking you will find. They are known to clock up to 300MHz. Again, there are cheaper solutions than this and expensive ram is not the best bang for your bucks on a A64 system.
 
Rseven, how do the new, smaller chips from micron stack up agains the ones in the old Ballistix? I haven't been keeping track the last couple months, but I recall people saying the new ones wouldn't OC as well because they produced about the same heat but had less surface area.
 
Otter said:
Rseven, how do the new, smaller chips from micron stack up agains the ones in the old Ballistix? I haven't been keeping track the last couple months, but I recall people saying the new ones wouldn't OC as well because they produced about the same heat but had less surface area.
I haven't heard anything one way or the other. What I have heard is the regular Crucial are being made with the Micron 5b D chips again instead of the UCCC, which means the regular Crucial are once again the best thing in value 2x1gig sticks. Pirate_Freder, you may want to consider those if you are a big gamer.
 
I am a big gamer but I am also a big oc'er, this is why i was going for the 1:1(thats how i run it with my barton :) ). so what is the BEST 2x1gb ram out there? also though how is it that there isn't much of a performance loss when your ram is at a lower fsb and can't handle all of the information being sent to it cause it should then bottleneck and cause a fairly large drop in performance, at least that's how i know of it as on 32-bit platfroms
 
The problem with the old XP platforms was the memory controller was on the Northbridge. Setting the ram at a different speed meant the two were async and time was lost in the process of adjusting the ram to different speed than the CPU. In the A64's the controllers is in the CPU and you can run the ram at any divider you like without a penalty. The performance gain of running your ram at 300MHz is quite modest. If you have to loosen your timings too much in the process you can actually loose performance.
The Crucial Ballistx as the rep as the best OC'ing 2x1gig ram, but there is other good stuff out there from OCZ.
 
There is a lot of misinformation on the net. Also, that may be a very old guide from before that whole idea was debunked. I'm not saying there is no benefi to be derived, because in some cases there is some performance gain. It's just not very much. Check out Otter's link above and it shows you how little you would gain. If it's worth it to you, then go for it.
 
Bang for buck wise that makes the most sense. You may want to check out this thread on 2x1gig sets.
http://www.ocforums.com/showthread.php?t=418741
If you can get the Crucial with the Micron chips you can have decent overclocking ram for a bargain price. you would just need to be carefull about getting older UCCC stock.
And I forgot,
:welcome: to the Forum!
 
actualy i've been here and active for a few ,months now :p, but thank you. are you talking about the crucial 3200 not the 4000? cause i didn'tlike the looks of the 3200, for one thing it doesn't even have heat spreaders, that can't be a good sign :p
 
No heat heat spreaders is actually a good thing. Many folks here peel them off because they seal more heat in that they spread. Also, when you use active cooling it makes for better airflow. The 3200's are fine, the 4000 will guarantee you that higher clock, but most of he 3200's will get there anyway.
 
well i looked at your link and combined with all of your guy's help it looks like i'll be getting the crucial ballistix pc-4000 2x1gb :), so thanks for all your help guys :D
 
Good luck, Freder. Let us know how it turns out.

Pirate_Freder said:
also though how is it that there isn't much of a performance loss when your ram is at a lower fsb and can't handle all of the information being sent to it cause it should then bottleneck and cause a fairly large drop in performance, at least that's how i know of it as on 32-bit platfroms
That's just it, even at 200MHz the RAM should be able to keep ahead of the CPU. Faster RAM will improve your performance only in situations where vanilla RAM couldn't keep up with the CPU, and in most real-world applications, that doesn't happen very often.

The big bottleneck when running asyncrhonously on older platforms came from increased latency at the FSB rather than the actual performance in the RAM itself. The problem was that with the RAM out of synch with the bus, the RAM would often miss the edge of the bus clock signal and have to wait for the next one. This added enough cycles that performance suffered noticably.

With the A64, the memory controller and RAM have a bus all to themselves, hence the memory never has to wait for the edge of the FSB clock. In fact, there isn't actually a FSB in an A64 system. The frequency commonly referred to as the FSB is actually the HTT base frequency. It's not a bus at all (no data is transmitted over it). It's just a frequency used to calculate several other frequencies in the system.
 
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