PDA

View Full Version : Does Lightwave support Hyperthreading?



yoshiii
02-08-2015, 08:02 PM
Hello

Does Lightwave support hyperthreading?

Have to decide between the i7 4790k and the i7 5820K.

Kryslin
02-08-2015, 10:48 PM
As lightwave picks up the number of cores from the Operating System, the answer to the question is no. However, the OS will see a hyperthreaded processor, and see double the number of cores; My old i7-960 shows up as eight cores under Windows 7, but it physically it only has 4.

Hyperthreading is meant to be completely transparent to the end user. If your processor has it, and the OS supports it, then all Lightwave will see is what the OS reports, which will be 12-16 "cores".

And since Lightwave supports multi-threading, it can (and will) use all those cores, real and virtual.

spherical
02-09-2015, 04:38 PM
Trying to keep things from becoming confusing to a person just starting out, the above end result all boils down to "yes", as far as the user is concerned. How the application achieves the use of two threads per core is essentially moot.


Intel® Hyper-Threading Technology (Intel® HT Technology)1 uses processor resources more efficiently, enabling multiple threads to run on each core. As a performance feature, it also increases processor throughput, improving overall performance on threaded software.


Hyper-Threading Technology is a form of simultaneous multithreading technology introduced by Intel. Architecturally, a processor with Hyper-Threading Technology consists of two logical processors per core, each of which has its own processor architectural state. Each logical processor can be individually halted, interrupted or directed to execute a specified thread, independently from the other logical processor sharing the same physical core.[4]

Unlike a traditional dual-core processor configuration that uses two separate physical processors, the logical processors in a Hyper-Threaded core share the execution resources. These resources include the execution engine, the caches, the system-bus interface and the firmware. These shared resources allow the two logical processors to work with each other more efficiently, and lets one borrow resources from the other when one is stalled. A processor stalls when it is waiting for data it has sent for so it can finish processing the present thread. The degree of benefit seen when using a hyper-threaded or multi core processor depends on the needs of the software, and how well it and the operating system are written to manage the processor efficiently.

This technology is transparent to operating systems and programs.

The OP should research on hyperthreading vs multithreading and read page 2176 of the LightWave 2015.1 manual.

Sensei
02-09-2015, 09:52 PM
Better illustrate it with render:
1 thread 217 sec
8 HT threads (4 cores) 42.1 sec

If they would be real 8 cores, it would be 27.125 sec
If they would be real 4 cores, it would be 54.25 sec

Better to have 42.1 sec than 54.25 sec. It's nearly 30% faster.