Intel Xeon E5645 2.40 GHz

[Make23l]

Hello everyone

I have a question that I can not understand what's going on
I have 2 types of computers with the following configuration
ComputerA
Intel Xeon E5645 2.40 GHz (2 processors)
24 Gig RAM
ComputerB
Intel Xeon E5-26 300 2.30 GHz (2 processors)
32 Gig RAM

Well I created a very simple scene, one cube, a plane and HDRI with bruteforce

establish a limit of RAM, 12 gigabytes.

Well, it would be normal that computerA, is faster, but not

computerA: 3:39
ComputerB 3:29

with more complex scenes the difference increases.
The computerA are new

Is there a problem with that kind of micros?
thanks

[Morbid Angel]

is your hyperthreading on or off? it could be due to the bucket size

[Make23l]

It is with the HyperThread ON, I rendered a test with hyperthread OFF with computerA and their time is

4:27 sg

I've rendered another test on another machine, computerC

Intel XEON E5-2620 2 GHz 2 processors
32 Gig RAM

3:43 sg

It is very rare that computerC computerA and give a result so close? the computerA is much more powerful.

Render size is 1400x602 and the bucket size is 87x37

Why can this happen? Any idea? Thanks Dmitry!

[Morbid Angel]

well the l2 cache sems different on the two processors? Im not an expert on the cpus but check that both cpus have the cpu throtteling or sometimes called intel speed boost on and any other option that may throttle the ghz down on idle time, this sometimes may affect the rendering time.

I also just did a bit of reading, the intel® Xeon® Processor E5-2620 seems to be more powerful, having more l2 cache and more gigathreads per second calculation may just be the reason why its a bit faster.

[Dariusz Makowski (Dadal)]

Humh, if they both are 6 core xeons running and simmilar MGHZ speed aka 2.8 ghz with turbo boost. Then they will be similar in speed. Its often better to buy older 6 core CPU than the newest one as they will be just as fast.. Unless more than a cpu code name changes...

[Make23l]

Do you think is better turn off The turboboost for vray rendering? I can try tomorrow, but its normal?

[Morbid Angel]

try with/without and see, in my tests on some xeons its a dramatic difference but likely you have a small render time difference between the two models so its probably not that. Just one cpu is slower then the other.

[Dariusz Makowski (Dadal)]

Yea run turbo. I if you google intelc CPU and go to their ARK website it says how much more speed you get from turbo boost. Keep in mind that there are 2 version(if I remember correctly) of turbo boost. The speed also differ if you turbo boost run on 1 core or on 6. For example 1 core turbo boost can give you 3.0 ghz where as 6 core turbo boos would give you 2.7ghz or so from 2.4 ghz nominal.

[Make23l]

Ok, I try this

ComputerA
Intel Xeon E5645 2.40 GHz (2 processors)
24 Gig RAM
Without Turboboost and the time is

3:47 sg

8 second slower

I don't understand nothing

[Make23l]

ComputerA VS computerC

http://cpuboss.com/cpus/Intel-Xeon-E...20#performance

[Dariusz Makowski (Dadal)]

Heya

Soo what did you expect to see?

Just because intle xeon X5 26xx is a newer model and released later it does not men it will be 25%+ faster than older E56xx version...

If they both run at the same speed or similar then they will render at simmilar speeds.

Btw cpuboss.com is quite cool web !

[hellobard]

well, if you check the specs, computer B has 15 MB cache and a max turbo freq. of 2.8 Ghz whilst Computer A has only 12 MB cache and a max turbo of 2.67 Ghz. Might be something in the cache, might be a bit in the turbo. Computer B is actually from 2012 whilst A is from 2010, so differences in architecture will be massive.

a: http://ark.intel.com/products/48768/...-GTs-Intel-QPI

b:http://ark.intel.com/products/64593/

It|s not all in the ghz.

[Make23l]

You are right it is a misunderstanding with my provider
Thank you very much to all!