Dual Processor vs. Single Processor

[royli57]

Hi,

I am looking to build a server with high SQL database usage. We will be hosting several forums that we hope will grow to be quite large.

This is my question. I am looking toward an AMD based solution with RAID1 SCSI hard drives, with about 1gb DDR memory. I am considering single/dual Opteron, or dual AthlonMP.

In the case of the AthlonMP, one could either use dual 1.2ghz, or a single 2400+ or 2600+. Is there a difference between 1.2x2 and a processor with double the clock speed?

What will make the most impact for a forum oriented server?

Thanks,
Roy

 

[myocardia]

Roy, wrong forum. You're much more likely to get a viable response from the networking forum, since these are the guys with the networking experience.

 

[beatle]

I don't know how this is a networking question...

A 2400+ or 2600+ doesn't have double the clock speed of a 1.2. The 2400+ runs @ 1.93GHz and the 2600+ runs @ 2.13GHz. A dual CPU system (say dual 1.2 GHz cpus) won't perform as fast as a single 2.4, given similar architecture. Your improvements might be 50% - 70% better depending on the application, not 100%. I would go with as much memory as possible and RAID 5. RAID 1 is nice if you absolutely need as much uptime as possible, but it doesn't really improve performance. For the CPU, a duallie would be nice, but they come at a price...

Oh, and welcome to the forums.

 

[ToxicWaste]

beatle is right on. You can expect about a 75% performance boost for the 2nd cpu and about a 50% boost for each cpu added after that. So, a dual 1.2GHz isn't equal to a single 2.4Ghz it would be closer to the performance of a single 2.1GHz cpu. A quad 1.2GHz would be equivalent to about a 3.3 GHz cpu (assuming they are the same architecuture, etc...) So, your best bet is probably a single CPU. Of course, a single Pentium 4 of the "C" variety shows up as a dual cpu under windows and linux...

 

[royli57]

Hey, thanks for the answers! I suppose I will look toward a single higher processor solution if there is no reason to go DP.

A have a question about comparing memory also. For my DDR memory, I think I understand ECC/non-parity, ECC has some redundancy for bit checking. However, is there a big difference between Registered/Unbuffered? Should I spend money getting more cheaper memory? Or do I need both ECC and Registered?

Thanks again,

Roy

 

[royli57]

Oh one more thing about the processors:

I can get a single Barton chip with a faster clock speed than a single Opteron for the same price. Is there a reason I would get the Opteron (stability, more performance per clock cycle, etc) in this situation?

Thanks,

Roy

 

[jdogg707]

You might go with the Opteron if you were looking to run 64-Bit Optimized software, like a version of Linux with 64-Bit support. Other than that, the Opteron has enhancements like a true Dual-Channel Memory Controller onboard, 1MB L2 Cache oppossed to 512KB on the Barton, and the boards designed for the Opteron are more tailored for Server use (64-Bit PCI Slots, More Memory slots, etc.). I would go with a Single Opteron, but get a SMP board with two CPU sockets, that way you can add another in the future if you find you need the boost.

 

[Goatsan]

why not 2 fast cpus? i've heard that connecting the L5 briges (or 1 of them) will turn it into an athlon MP

 

[myocardia]

Originally posted by: royli57
Hey, thanks for the answers! I suppose I will look toward a single higher processor solution if there is no reason to go DP.

A have a question about comparing memory also. For my DDR memory, I think I understand ECC/non-parity, ECC has some redundancy for bit checking. However, is there a big difference between Registered/Unbuffered? Should I spend money getting more cheaper memory? Or do I need both ECC and Registered?

Thanks again,

Roy

Roy, the type of memory that you buy will depend on the type of motherboard you're going to use, and the type of motherboard you buy will depend on the type of processor you use. It's that simple. If you plan on using a server motherboard, whether it's dual cpu or single, it's going to require ECC registered ram. You can't put any of this cheap, non-ECC ram in them. You're going to get much better performance by getting an Opteron, but it kind of sounds to me like you might be trying to save some money. If you are, why not build a quasi-server, with a 3.0 or fast P4C. That would allow you to use cheaper, faster ram, and a motherboard that costs less than half of what a server mobo costs. If, over time, you acquire more traffic than it can handle, then you could invest in an Opteron DP and some ECC ram, since obviously your business would have to already be "off the ground" and bringing in some cash flow.

 

[myocardia]

Originally posted by: beatle
I don't know how this is a networking question...

Nobody said this was a networking question, beatle, but the only people on this entire site who have experience using/comparing single proc. servers and dual proc. servers while running server OS's hang out in the networking forum. Have you ever heard of an overclocked server??

 

[VIAN]

If its a dababase system, then why dont you go Intel with much higher bus speed. I would give you more performance.

Dual processors suck. Its right on the otherside of the price/performance scale.

 

[royli57]

Hi,

I have been researching the past few days and this is what I have finally decided.

I am tring to build a performance oriented but not overly priced system.

The top choices for performance seem to be either dual opteron/dual xeon/dual athlon MP. The Xeon is too pricey for the price I am trying to hit, so I am left with dual opterons or athlons.

Dual opterons are the best performing system for most server applications (based on anandtech reviews) but they cost 400 for the motherboard and 200 each for 1.6ghz processors. The dual Athlon MP 2ghz cost 100 a piece and the motherboard is only 200. Although the Opteron cycle for cycle is a better chip, the Athlons have more clock speed to make up for it. The Athlon system would cost half the price of the Opteron for roughly the same performance.

The 2ghz Athlons have Barton cores with .13micron to boot, meaning there is less heat. Any other suggestions about this setup are appreciated.

Roy

 

[Mingon]

I have 2 x 2500+ bartons modded to MP and running either 2.266 (2.4 capable) the performance is very good. But you start to notice other things slower your machine i.e hard drive (are you going dual 10k or 15k? I have 2 15k's I keep meaning to setup)

 

[jdogg707]

The only problem with modding the 2500's is that AMD has capped them and put that protective layer over them, making it hard to modify the bridges.

 

[Mingon]

yeah its a pig, but you can also fill the pits.

 

[dguy6789]

This will help you understand. A dual 1.2GHz is NOT like a 2.1 as someone said.

http://www.ocforums.com/showthread.php?s=&threadid=78677

Read it all, and you will become enlightened on dual cpu processing.