Is DDR2 RAM going to be a bottleneck?

[Manisjos]

Good evening yall, I recently required an older Dell server I plan on using as a NAS for web server storage, databases, backups, and possible lightweight vms.

The only thing is, it has DDR2 667 Mhz RAM. I wanted to ask if this is going to be a bottle neck or affect my performance heavily. I figured I would ask before I waste my money on a new board and hardware for it. I have looked through and read some threads, but I apologize if I missed this already being discussed.

Thanks, I appreciate any input.

 

[jgreco]

So, here's the answer.

Your system's memory is somewhere in between the speed of hard disk and the very latest fastest newest DDR5 RAM.

It is quite a bit closer to the speed of that DDR5 RAM, but it is sorta tragically slow given that DDR3-1333 was quite common a decade ago, and it's half as fast as that. Yet a DDR3-1333 system is very serviceable today. Not stellar rocketship lightspeed fast. But it's a lot faster than HDD, and ZFS thrives on cache.

So just try it. See how it works.

 

[sretalla]

I'm not sure that I can remember that far back, but I don't know if "throwing a lot of RAM" at the problem is even an option with DDR2 given the architecture limitations at that time... what's the maximum for a board/CPU/chipset at that time? 16GB?

I see reference in searches to 512MB, 1GB and 2GB DIMMs. 8 RAM slots on a board would be as much as I recall ever having seen in that era.

 

[rvassar]

I started out with an old Dell Poweredge SC1430. It supported 16Gb of DDR2, and two LGA 771 CPU sockets. I dropped a couple 4 core Clovertown CPU's in it and tried using it for a couple months 5+ years ago... It may still be in my .sig below.

It worked, but had some significant drawbacks:

1. The onboard SATA ports were slow, and had trouble with larger drives.
2. PCIe 1.0? Maybe it was 2.0... But it still had motherboard real estate for PCI, parallel SATA, etc...
3. The Clovertown CPU's I used were 150 watts TDP each, and Intel didn't really do power management very well back then. This thing would drive you out of the room with heat and fan noise. It would chew thru $25/mo in electricity just idling.
4. Not enough RAM for Jails/VM's. TrueNAS needs 8Gb by itself, and the middleware layer has grown in recent years. I've recently bumped my 16Gb DDR3 Ivy Bridge server to 24gb, and soon 32gb just to stay serviceable and put off a motherboard upgrade for another year or so.

 

[Arwen]

My AMD Opteron Barcelona had 16 DDR2 DIMM slots, (though if I went over 8, speed dropped below 667Mhz). It had 4 x 2GB DIMMs, so with 8 x 2GB it would be 16GBs. It did support 4GB DIMMs, for 32GB, (8 slot), or 64GB, (for all 16 slots), maximum.

The server was a 2006 era Sun Microsystems X2200 M2 1U server. Great machine for it's price, (though I guess I got employee discount...).

 

[danb35]

IIRC, the big issue with Intel-based boards of that era wasn't the DDR2 RAM as such; it was the front-side bus that crippled all the data transfer rates. AMD boards didn't have that issue. But we're dealing with some very old kit, so my memory could be off.

 

[Arwen]

IIRC, the big issue with Intel-based boards of that era wasn't the DDR2 RAM as such; it was the front-side bus that crippled all the data transfer rates. AMD boards didn't have that issue. But we're dealing with some very old kit, so my memory could be off.

Oh, right. I had forgotten that the AMD Opteron was one of the first x86/x64 server CPUs with direct memory channels, (in my case, I think 2 per socket).

When I ran a ton of DVD extract & transcodes to MP4 x264 advanced CODEC, that Opteron dual socket, quad core per socket, (8 cores), server with DDR2 ran just fine compared to a newer quad core AMD Athlon, with DDR3. (Both were running 2 DVD extract & transcodes at once.)

But, as @danb35 points out, some really older Intel designs have front side bus as the path to memory. Much slower than today, (or my really old AMD Opteron server).