1.25GB Single channel vs 1GB Dual Channel 400MHz DDR1 RAM
I am considering a basic upgrade to my rig (in my sig).
I am planning to buy an extra GB of RAM so that I can run KDE4.1 and other RAM intensive apps.
I have 2 slots for DDR RAM, and one slot is occupied by a 256MB DDR1 400MHz stick. I want to know if I will get better performance by inserting 1GB in the other slot, or by removing current stick and going 512MB + 512MB dual channel.
My motherboard has no expansion slots except two PCI slots and a PCIe x1 slot, and I have onboard GMA 900 Graphics. You can see that gaming is clearly not my priority, yet I older run games like Unreal Tournament 2004, Urban Terror, Quake 3, etc on linux and GTA 3/VC/SA, Halo, Counter Strike and DoTA on windows. But I care more about performance while compiling, opening lots of tabs in firefox, multitasking, etc than about gaming, unless I get a really huge boost while gaming.
On linux, I currently manage to game at minimum settings on Urban Terror with 100FPS by launching it on archlinux from startx command by placing urban terror in .xinitrc. I know its somewhat cheap, but the performance boost is huge. I got a good boost by changing the VRAM in the BIOS from 8mb to 32mb and launching the game this crazy way to save resources.
Other than gaming, I plan to shift to Gentoo 64bit and do a lot of compiling. I plan to use RatPoison, IceWM, Xfce and KDE4.1 as my WMs/DEs. I often do things like listening to music, running a download client, running firefox, running a bittorrent client, running system-updater, and a simple app in wine at the same time.
Please advice, as I am going to buy the ram very soon.
Here's a benchmark comparing dual to single channel:
The difference is small enough that if I were you I would go for 1.25GB.
Thanks. But what about stuff like compile times ?
Just an idea here but:
Go with the 1Gb stick and add another 1Gb when you can afford it.
Also look at the possibility of buying a MB/CPU combo that uses DDR2.
The local store has 2Gb DDR2 for $25. Two sticks of 1Gb DDR mem is $75
4GB DDR2 RAM (2x2GB), even low-latency 4-4-4-12 800Mhz, costs 65$ (50€ here.) I know because I just bought it a week ago
So 75$ for only 2GB is WAY overpriced.
Yeah that's my point. DDR2 is much less than half the cost of DDR. At least here it is. I think they are trying to discourage upgrades and get us to buy new gear all around.
Originally Posted by RealNC
Anyway, to get back to the OP, more RAM is always better when you need to choose between dual channel and more RAM. Dual Channel is useless. Yes, I benchmarked it actually. No difference whatsoever, unless you call a 1% faster throughput a "difference".
Originally Posted by RealNC
I did have a P4 3.0 HT on which the dual channel gain was supposed to be the most noticeable in real life.
I changed for another P4 which wasn't dual channel and then I switched it back to dual channel after having picked up the memory sticks of my previous P4.
Result : no visible difference. even in games (UT2K4).
But, please, don't buy "no-name" memory. Go for any brand you like or you'll find at your favorite retailler (corsair, kingston, geil, g-skill, etc.), they all have value ram which is far enough good if you don't plan to overclock your rig.
I've tried several times to show significant improvement with going dual channel and have only seen a difference once on a low end onboard graphics machine when I went from single channel 266 to dual 400Mhz ddr.
Swapping tyhe same sticks of mem in a system with a video card gave no noticeable difference.
DDR2 can only help speed up if you need large amount of data transfered between CPU and memory (which is very unusually in desktop use). In real world it is more important that memory has low latency to give applications performance gains.
But of course also amount of memory is very important if multitasking ... you know how slow swapping is. I would choose more ram over a bit more expensive and a bit faster ram. Of course there is some limit to how much memory can be useful but if you use DVCS for a large size project it can be good idea to have 2G+ memory. That way repository and compiled files can be cached in memory same time giving huge speed when doing some hacking.