Dual Processor vs Dual Core

[MatthewLTL]

Since I have my DP 1.25 coming for my MDD and knowing that the G5 was in both DP and DC it got me thinking....

With PowerMacs (Specifically the G5) What has better preformance? A Dual Processor Single Core G5 or a Single processor Dual Core G5?

Now i know all the process or Dual Core vs DP with Windows Servers but since DP PowerMac (the G4s anyway) dont have 2 RAM channels like DP PCs do i assume the PowerPC DP/DC setup is different

 

[Intell]

The dual cores often perform better at the same clock speed.

 

[redheeler]

The dual cores often perform better at the same clock speed.

They also consume less power.

 

[Anonymous Freak]

It largely depends on the workload. If you're doing something that isn't bandwidth intensive, and is similar enough that it has multiple threads doing similar work on the same data, then dual-core will be better.

If you're doing something that is bandwidth intensive, and sends noticeably different data to multiple threads, then dual-socket would be better.

Dual-core shares a single socket for two threads, where dual-socket is separate - so dual-socket has more bandwidth available per core than dual-core.

(Although, admittedly, if you're that concerned about ultra-high-performance, you would be looking at something more modern than a G5... Even a previous-gen quad-core Mac mini would outperform any two-total-cores G5, and be very competitive to the quad-core G5.)

 

[bunnspecial]

One additional advantage of the DC G5s is that they use faster memory than the dual processor ones.

 

[redheeler]

(Although, admittedly, if you're that concerned about ultra-high-performance, you would be looking at something more modern than a G5... Even a previous-gen quad-core Mac mini would outperform any two-total-cores G5, and be very competitive to the quad-core G5.)

Even a dual-core 2012 Mac mini would outperform the best quad-core G5 no problem.

 

[gavinstubbs09]

I actually did this just a few days ago, geekbenched my Early 05 2.3 and my Late 05 2.0 and the DP smokes it in almost everything except stream performance.

http://browser.primatelabs.com/geekbench2/compare/2477454/2540556

 

[gavinstubbs09]

They also consume less power.

The Early 2005 2.7 had a 650w power supply while all DC models feature a 710w power supply hence the stupid power cable specific to that model.

 

[bax2003]

I actually did this just a few days ago, geekbenched my Early 05 2.3 and my Late 05 2.0 and the DP smokes it in almost everything except stream performance.

http://browser.primatelabs.com/geekbench2/compare/2477454/2540556

Of course it is faster on CPU benchmark when that DP model is 300 MHz faster per CPU.

 

[desantii]

The DP in this case is 15% faster frequency wise but only 8% faster in Geekbench, so actually either scaling is not linear or the DC actually is performing better

Were't the DCs an updated version of the base G5 (e.g. some improvements in IPC)

I actually did this just a few days ago, geekbenched my Early 05 2.3 and my Late 05 2.0 and the DP smokes it in almost everything except stream performance.

http://browser.primatelabs.com/geekbench2/compare/2477454/2540556

 

[Surrat]

Dont forget that besides faster memory, and pci express, the dual core G5's also had double the L2 cache of the older versions.

 

[desantii]

Exactly...the later G5s (DC) should have some IPC improvements from the previous ones (DP) from the cache, other tweaks?, faster components

Dont forget that besides faster memory, and pci express, the dual core G5's also had double the L2 cache of the older versions.

 

[gavinstubbs09]

Of course it is faster on CPU benchmark when that DP model is 300 MHz faster per CPU.

Absolutely. I'm stating that the DC regardless of speed doesn't offer much over the DP.