X3 and hyperthreading

[lukethegordie]

Ok im abt of a noob when it comes down to real technical stuff.

I bought a p4 640 3200mhz which supports hyperthreading and i have some questions.

1 will x3 support multi-threading?

2 if no since hyperthreading is 2 virutal cpus will x3 only run on at 1600mhz or will it some how run at 3200mhz.

cheers in advance and sorry if this thread has already been made the search thingy is disabled

[martindemon]

Even if X3 would take advantage of hyperthreading, it would never give more computing power to a single core, non dual-cpu system. Hyperthreading support could help the game being more efficient computingwize if many threads are launched simultaneously. But I doubt any game do this yet and if so, they would be the exception. But with games like Oblivion, and the new drivers from Nvidia taking advantage of dual-core systems, now we will soon talk about benefits of having more than one physical core in a computer.

[lukethegordie]

Ok so if this is the case wouldnt x3 run better with ht disabled if its unable to use the second virtual cpu?

[Mareel]

As Martindemon says there are no real benefits to hyper threading as far as current games go unless the software is written to take advantage of it and in extreme cases it can adversely affect performance.

99% of games at present are single threaded applications but a couple of titles are appearing this year that will take advantage of Dual core technology.

I would say keep HThreading enabled,i dont think you would see any difference either way.Your CPU will be more than enough to run X3.

[The Asgard]

regardless if X3 supports threads or not your OS will still be sitting in the background doing its own thing and will always benifit from a 2nd core or to a lesser extent HT Tech.

[lukethegordie]

cheers for help. i guess ill just have to wait and see how well it runs and go from there.

[youki]

Recently, I came across a compatibility issue between AMD dual-core processor and a game called Roseonline. When in game, everything appears in slow-motion. All the other games I have run ok on my system. First I thought it’s my graphics card, but after further searching on the official website and on the net, I found a known performance issue with dual-core processor on some games. I hope X3 has been tested against this scenario.

Detailed issue description and possible solution is available in this article on Microsoft website. There’s also a good discussion from other users here.

My system specs:
WinXP Pro SP2 with directX 9.0c (4.09.00.0904)
AMD Athlon(tm) 64 X2 Dual Core Processor 4200+
xFx NVIDIA GeForce 7800 GTX (490Mhz)
MSI K8N NEO4 PLATINUM SLI
CORSAIR XMS 1GB (2 x 512MB) 184-Pin DDR SDRAM Unbuffered DDR 550 (PC 4400) Dual Channel Kit System Memory

[softweir]

One of the devs has already mentioned (a while back) that the X games do not use multiple threads, and therefore do not benefit from hyperthreading or dual-core. They will run on dual-core and hyper-threaded cpus, but to no particular advantage.

I'd search for the post but the search function has been disabled for the time being.

[shadowfawx]

Ok im abt of a noob when it comes down to real technical stuff.

I bought a p4 640 3200mhz which supports hyperthreading and i have some questions.

1 will x3 support multi-threading?

2 if no since hyperthreading is 2 virutal cpus will x3 only run on at 1600mhz or will it some how run at 3200mhz.

cheers in advance and sorry if this thread has already been made the search thingy is disabled

Hyperthreading is not the emulation of 2 virtual cpus.... It is simply the ability to double the throughput of your DDR memory which runs at 400mhz into an 800mhz bus. Which in turn streams data between memory and processor at twice the normal rate (not using HT technology).

Will the game make use of this technology. Yes. It is not software dependent.


The use of multithreading (aka Dual Core CPU's) is on the other hand software dependent. I doubt seriously this will be taken advantage of by X3.

[lukethegordie]

Ok im abt of a noob when it comes down to real technical stuff.

I bought a p4 640 3200mhz which supports hyperthreading and i have some questions.

1 will x3 support multi-threading?

2 if no since hyperthreading is 2 virutal cpus will x3 only run on at 1600mhz or will it some how run at 3200mhz.

cheers in advance and sorry if this thread has already been made the search thingy is disabled

Hyperthreading is not the emulation of 2 virtual cpus.... It is simply the ability to double the throughput of your DDR memory which runs at 400mhz into an 800mhz bus. Which in turn streams data between memory and processor at twice the normal rate (not using HT technology).

Will the game make use of this technology. Yes. It is not software dependent.


The use of multithreading (aka Dual Core CPU's) is on the other hand software dependent. I doubt seriously this will be taken advantage of by X3.

Your thinking of Dual channel, which is used by both Intel and amd systems to double the 400fsb.

HT is a dual core emulation. unfortunately Intel doesn’t explain this in layman’s terms. So I don’t know if x3 will make use of the full 3200 MHz or just 1600 MHz.

I have other games that I know don’t support HT that require 1700 MHz and run great. I think HT can allocate different amounts of processing power to each virtual CPU depending on demand. Otherwise half my games would run turd.

BTW I have found a number of games that support HT. MOHPA, Empire earth 2, Battle for middle earth.

I think there is some big differences between an HT system and a Dual cpu system. Its just a pity Intel don’t explain what half the features do.

[softweir]

Suggest you look up the Wikipedia HyperThreading Technology entry.

As I said before, the X games don't use multiple threads, so hyperthreading and dual-core are of no benefit to them.

[CentaurusA]

I dont care about hyperthreading since there is not much advantage(in some cases performence decreases) at all to that since it is a virtual core/processor, and not an actual physical core.

I was wondering if X3: Reunion will take advantage of duel core processors, such as the AMD Athlon 64 X2 series of processors and give them a performence boost, or if not, I guess I will just play X3: Reunion while defragmenting+scanning with Norton Antivirus+scanning for spywayre/adware on my other core without a performence decrease. Personally I would prefer option #1, though #2 also sounds tempting

Egosoft willing to answer this at all?


reason for this post: look at signiture for system specs.

Also, on a side note, I am creating a new thread instead of adding to the "hyperthreading" thread because hyperthreading works much differently than true duel core, and are not very compatable topics. So dont flame me for posting a new topic since the other one I saw was still too different of a topic IMO.

[The_Abyss]

I dont care about hyperthreading since there is not much advantage(in some cases performence decreases) at all to that since it is a virtual core/processor, and not an actual physical core.

I was wondering if X3: Reunion will take advantage of duel core processors, such as the AMD Athlon 64 X2 series of processors and give them a performence boost, or if not, I guess I will just play X3: Reunion while defragmenting+scanning with Norton Antivirus+scanning for spywayre/adware on my other core without a performence decrease. Personally I would prefer option #1, though #2 also sounds tempting

Egosoft willing to answer this at all?


reason for this post: look at signiture for system specs.

Also, on a side note, I am creating a new thread instead of adding to the "hyperthreading" thread because hyperthreading works much differently than true duel core, and are not very compatable topics. So dont flame me for posting a new topic since the other one I saw was still too different of a topic IMO.

I've merged your thread with the virtually identical existing one about 20 pixels away... Please at the very least have a look before posting. Both Hyper threading and dual core are in discussion here.

[softweir]

I was wondering if X3: Reunion will take advantage of duel core processors

One of the devs has already mentioned (a while back) that the X games do not use multiple threads, and therefore do not benefit from hyperthreading or dual-core.

[LordSuch]

I think there is some confusion here between hyperthreading (HT) and dual / multiple core technology. To clarify a HT enabled processor emulates two cores, however if you run just a single (threaded) process then you will see no (or very little) performance difference. A HT enabled 3.2 GHz processor is always a 3.2 GHz processor.

With dual cores, things are slightly different as there are actually two physical CPU's but just combined onto a single chip. In this case with a 3.2 GHz dual core processor you would get (hypothetically) twice the performance from an application that used two threads / processes and therefore you could argue that only half the CPU is only being used if the application is not designed this way - however given the speed of modern dual cores even when using a single core the processor is likely to be more than fast enough.

As for X3 - the thought seems to be that it will not be multi-threaded and therefore will not take advantage of either HT or dual core CPUs.

Personally I thought there would be a fairly easy seperation of labour for at least two threads within the game engine. No doubt we'll find out for sure by the end of the week.

HTH

LS

[lukethegordie]

Ok looking at the site softweir gave me and looking at the intel website i have came found the answer.

1 No x3 dont support HT as most of you stated before

2 HT does not mean 2 emulated cores running at half-MHz of the total clock speed. The core of my CPU is always 3200 MHz. The CPU Has (what Intel calls) 2 Architectural States instead of one. Enabling the CPU to multi-task. If a program uses multi-threading then the resources are split between the two Architectural States making it more efficient. But if I use a program that is single threaded then all or most of the resources are allocated to just 1 Architectural States.

Confusing maybe, but at least I now know my CPU will run X3 and any other non multi-threaded game at 3200 MHz or near enough.

I hope this sorta explains it to other people with HT CPUs.

Cheers for all your help

[pjknibbs]

I think you are also confused, LordSuch. A hypterthreaded CPU actually has more processing units in it than are required for a single processor core, but not enough to become a full-blown dual-core CPU. The extra processing units allow it to function as a kind of one-and-a-half processor rig--so in fact, the second processor isn't entirely an emulation trick, and neither is it a true second CPU.

The actual benefits of this setup are debatable. Certainly the performance improvement you get on multi-threaded apps is not that great with HT, and you CAN get a small performance loss on single-threaded apps due to the overhead of running HT; however, this performance loss is pretty negligible--it's the order of a couple of percent. Most certainly a 3.2GHz HT CPU isn't going to be so crippled as to perform like a 1.6GHz CPU when running single-threaded apps!

[lukethegordie]

lol you beat me to it pjknibbs nice explaination, makes more sense than mine

[CentaurusA]

sorry about that...personally I just see a large difference between hyperthreading and actual duel core cpu's, how they work, and how much performence gain is possible. Besides, isnt the programming needed quite different when trying to get a performance gain from a physical cpu + a virtual cpu compared to 2 physical cores in 1 cpu? Please correct me if I'm wrong.

[Boogle]

Would just like to clarify a few HT-related questions and answers:

HT is not emulation, it doesn't pretend to be something it isn't. HT also isn't new, its been used in other CPU architectures very effectively; Intel's version of it is purely to get more performance out of the P4 as opposed to genuinely trying to cheaply increase raw performance. So how does HT work?

Well as you know, the P4 is deeply pipelined, this means there are many stages to the pipelines. This is the key feature that lets Intel's implementation work. You send instructions down the pipeline, they're executed and the results output to memory. Huzzah for that. Now, what if an instruction doesn't use the FPU (Floating Point Unit) on the P4? Thats effectively one unit wasted that cycle.

Here's where HT comes in, it reports to Windows that there are two processors. The Windows schedular will then send threads to both 'CPUs' as it would in any dual-CPU setup. This means the processor can effectively see two independant execution threads. I'm going to overly-simplify here, so don't take this as gospel:

While processing thread #1, the second FPU may be free, as well as the first ALU. If there are instructions waiting for the FPU and/or ALU on the second thread - they are executed there and then. This essentially means units are left idle far less in an HT-enabled CPU. A branch mis-prediction causes a similiar (and much more dramatic) event. If a branch is mis-predicted, then the entire pipeline must be cleared. This is great news for the second thread because it suddenly has access to almost the entire pipeline for a fair few cycles (I used to know how many, but been out of game dev for too long :\).

Of course HT has some very clever logic contained within it - and in fact the first version of HT to appear in the P4 was HT v2. This logic is essential to keeping performance, otherwise you really would be in a situation where threads have 50% of the CPU each as opposed to an unbalanced share which they should have. You wouldn't really want your game to run at half the speed it should because you're receiving an email in the background.

HT also can't work miracles - if the units are in use, then they're in use. So it would be impossible, for example to encode at twice the speed because the units the second encoder needs are already in full use by the first encoder. There will be a slight performance increase due to HT, but it will be small.

Oh - if you're wondering why the deep pipeline helps - its because there are more units available and branch mis-predictions are a much more major event.

Genuine processors designed with HT (forget the real technology name) in mind from the get-go generally double important units like the FPU/ALU.

Hope this helps