what's more important, clock speed, physical cores, or cache

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panzeroceania
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what's more important, clock speed, physical cores, or cache

Post by panzeroceania » Sat Oct 11, 2014 10:57 pm

for Exodus, what will help increase performance best? top clock speed? number of physical cpu cores? L2 cache? L3 cache?

which would be better suited for Exodus?

Intel Core i7-4790K -- http://www.newegg.com/Product/Product.a ... 6819117369

Intel Core i7-5820K -- http://www.newegg.com/Product/Product.a ... 6819117402

panzeroceania
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Post by panzeroceania » Mon Oct 13, 2014 6:00 pm

What about this processor? it's dual core, 512k L2 cache, and 3MB L3 cache. base clock speed of 3.2Ghz, overclockable up to 4.7Ghz, possibly more

Pentium G3258 Anniversary Edition -- http://www.microcenter.com/product/4351 ... _Processor

it's only $60 USD. It seems like it should perform well in Exodus. At least if you are willing to overclock it.

How would you compare the pros and cons for use with exodus of the 3 CPUs listed above?

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Jazzmarazz
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Post by Jazzmarazz » Mon Oct 13, 2014 6:02 pm

Does exodus support multithreading?

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Shadow
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Post by Shadow » Mon Oct 13, 2014 8:53 pm

panzeroceania, you need quad core processor Core i5 3570K (or 4670K) atleast with 3.9~4.0Ghz clock speed, for run all romset on fullspeed.

Exodus have better experience with quad core CPUs than with Dual core.

For example even at 4.3Ghz with locked cores to 2 threads, my core i7 3770K can't run games at good frame rate, it jumps around 56-70fps. With 4 threads goes up to 90-130fps.

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Post by Nemesis » Thu Oct 16, 2014 12:22 am

For the Mega Drive, you want at least 4 physical cores. The Z80 and M68000 spend a lot of time locked together. In the next version of Exodus they'll collapse together into one thread when this occurs, but in the current release version they each take a thread. The advancing of these processors is the "critical path" in advancing the emulator. You want these execution threads to have a core to themselves as much as possible, without being switched out by anything else. Apart from the M68000 and Z80 execution threads though, you've got the VDP, PSG, and YM2612 render threads, the GUI thread, and various command and control threads and spin-off threads from various devices that become active from time to time. If you only have 2 physical cores, all these other threads are stealing time from the critical path of the emulator in order to do their work. Having 4 physical cores is a good balance, as the rest of the threads should be able to easily work within the remaining 2 cores. Having 6+ cores will probably give little benefit on the Mega Drive (until 32x and MegaCD support that is).

So, your number one priority is 4+ cores. After that, your next most important consideration is actually the microarchitecture. Remember that just because a processor runs at a high clock speed, doesn't mean it can run code faster than another processor with a slower clock speed. There are a massive number of factors that effect how efficiently a processor can run code. I would recommend the Intel Core i7 processors in all cases. Nothing else I know of is nearly as powerful as this architecture, regardless of clock rate.

So, you want a 4+ core i7 processor. Within that, you want the fastest clock rate and newest architecture revision possible. This list would be a good place to start:
http://en.wikipedia.org/wiki/List_of_In ... processors
The Core i7-4790K for example would be an excellent choice. Quad core at 4GHz per core, with a 22nm Haswell architecture. It had a launch price of $339 in June this year. If that chip is out of your pricerange, get the best you can afford. As long as it's a quad-core i7, it'll be up to the job. My Core i7-920 for example is from 2008, and is the slowest, very first i7 processor ever released, with a 45nm Nehalem architecture and 2.67GHz per core. It can get full speed on Exodus.

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Nemesis
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Post by Nemesis » Thu Oct 16, 2014 12:47 am

Just realized I missed most of the content in your original post. Between the two specific processors you listed, the Core i7-4790K and the Core i7-5820K, both of them would be capable of running Exodus full speed easily. I would say that the Core i7-4790K is better though, because it has not only a significantly higher clock rate per core (4GHz vs 3.3GHz), but also much better turbo boost modes (2/3/4/4 vs 1/1/1/1/3/3). The turbo boost configuration is a major thing, you don't want to ignore it. The difference in turbo boost widens the effective clock rate gap by several hundred MHz more, meaning you'd probably get around 35% better performance from the Core i7-4790K I'd guess.

That said, getting a 6-core processor isn't a bad idea for the future. I expect trying to run both the MegaCD and 32x addons for the Mega Drive in Exodus might require a 6+ core processor to get full framerate. It depends on how often you upgrade your processor, and if you care about fastest possible speed now or if full speed is plenty, how much of a factor this is for you.

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