Cheepskate processor question

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Weesel
Posts: 10
Joined: Thu Apr 05, 2012 5:47 pm

Hi all, my first post!

I am considering buying a new PC and focusing on graphics card oomph most. That means, good power supply and room for expansion on the motherboard. And of course a nice GTX card.

But I wonder, if I am not interested in much else than Octane to start with, how much can I save on the processor? Well OK I think that it needs to be two-core miminum, single-core really is history now.

There are new AMD Fusion processors coming out later this spring. If I bought one of those, I would have AMD graphics embedded into the processor, plus a discrete NVIDIA card. That would be kind of nice. Of course, I am not planning to use the AMD graphics for Octane - only for stuff like Folding@home, testing and comparison, etc.

Anyone have any ideas? I suppose that modern processors are pretty powerful... but it won't hurt to ask ;)
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t_3
Posts: 2871
Joined: Tue Jul 05, 2011 5:37 pm

using on-chip amd graphics and a nvidia card at the same time might lead to problems, at least if the nvidia card is not used for main display. nvidia drivers seem to disable things like physx and/or cuda, if the driver finds amd graphics in the same system. don't know if this has recently changed... but there is at least no such problem with i7 and intel on-chip graphics - so this would be the saver bet imo.

octane needs some cpu power while voxelizing, but currently this is single-threaded (subject to change), thus a 2core running higher clocks would be sufficient. you will need quite a lot system ram also, i'd say 8gb is the minimum, depending on the scene sizes you plan to work on...
The obvious is that which is never seen until someone expresses it simply

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Weesel
Posts: 10
Joined: Thu Apr 05, 2012 5:47 pm

OK that's good to know... good thing I asked. Well RAM is pretty cheap these days, might as well go for more than 8G.

If AMD graphics is out, that still leaves many AMD processors to choose from... there was one interesting one with three cores.

But it might be better to go with Intel and one of their new Ivy Bridge processors if they come out soon enough. Have to wait and see...
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Reggie
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Location: Los Angeles

I assemble a lot of computers every year and I built my AMD 1090T machine almost 2 years ago and for $1,300 it's still very impressive. Single core performance is definitely slower than the intel CPUs, but in real world use, it runs so much smoother than most i7 or i5 machines that I just prefer the 1090T over them.

I recently had the opportunity to sell my computer for $900 and I was considering building a new Intel based machine, but I decided to keep my 1090T machine because it still runs so well, I just couldn't stand to get an intel machine to replace it! I use a 3.4 Ghz i7-2600 at work and I'm consistently disappointed with its hiccups and generally incosistent performance. It may be faster than my 1090T when running a benchmark, but honestly, it's quite frustrating on a daily basis.

The last two machines I built for my friends were based on the i5-2600 and the i7-3960. The i7 3960 is nice, but I think the lower end AMDs actually run nicer and are obviously much cheaper.
GTX 470 | 16 gigs | AMD 1090T | Win7-x64 | Maya til death!
Leiurus
Licensed Customer
Posts: 38
Joined: Thu Jan 26, 2012 3:30 am

@Reggie

It's quite interesting as I'm in a similar situation: my last rig was built more than 4 years ago and it still performs really very well, even though it was more between the mid-range / high-end zone than high-end / ultra high-end (around 1600SD), and I am now building my a new one, really ultra high-end this time.

However they are Intel based and to be honest it's been ages since I had feedback, especially a positive one, towards a AMD based system. May I ask you what you mean by "smoother" and "run so well"? And what are the inconsistency/hiccups of the 2600? I'm sincerely curious, I'm not an Intel fanboy.

@OP

My advice is conflicting with Reggie's one but I would not buy a low end CPU "to start with". I understand that you just want to start with Octane and nothing else but I would still buy a mid-range CPU with good 3D benchmark results, they are really not that expensive and if you want to give a try to CPU based render engines you will be extremely limited with a low end one. CPUs are not evolving that fast lately and a decent mid-range one will stay competitive for a few years, when a really cheap one can be outdated pretty quickly. If you build a GPU oriented machine you will anyway go towards a high-end configuration: powerfull PSU, room for expansion slots (which generally means large ATX / E-ATX motherboards), large case, decent amount of RAM, etc...I don't really get the point of setting a very low-end CPU in such a system, when it comes to 3D WS trying to cut cost too drastically often lead to purely wasting money. Just my 2cts
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Weesel
Posts: 10
Joined: Thu Apr 05, 2012 5:47 pm

Yes, that's wise words. But then again, one option might be to buy a cheaper processor now and update later. That requires some studying and research, as the motherboard needs to be one that will support new processors as far in the future as possible.

My funds are quite limited at the moment, because I have been studying (at an old age) and I am not really sure how much I will be earning in the near future. That's why I think of ways to shave off some of the cost.
Weesel
Posts: 10
Joined: Thu Apr 05, 2012 5:47 pm

Okay, here's another question. I tried to search for an answer a bit, it might be somewhere already, but I have not found it yet.

And this is the question: I understand that memory does not add up when using multiple cards. I understand that if there are two cards with 1G and one card with 512MB, then the total usable memory for Octane is 512MB. So far so good. But is it possible to "switch off" the 512MB card at will, in other words, can I tell Octane to forget about the smallest card and only use the two other cards with full 1G of graphics memory?

That would be neat - to either aim for max CUDA cores, or for max graphics memory, without needing to physically remove one card.

It is good to know answers to such questions when planning a rig for Octane. There's old Quadros for sale at a nice price which might be nice as number one card but the older models only sport 512MB. If they are too restrictive for Octane, then I shall not buy one.
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t_3
Posts: 2871
Joined: Tue Jul 05, 2011 5:37 pm

... this is possible. you can switch cards individually on/off in the settings.

if you have no use for quadro specialiced drivers (i.e. for max/maya/autocad/etcv viewports), then you shouldn't go this way. the cuda power (= octane performance) of quadro/tesla cards is no better than what their gamer counterparts provide (in fact they are a bit slower because of lower clocks)...
The obvious is that which is never seen until someone expresses it simply

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Reggie
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Location: Los Angeles

TL;DR - The AMD CPUs seem to perform like Xeons in my experience.

@Leiurus: First off, let me just say that I completely agree with your last point about "trying to cut cost too much and wasting money", that is absolutely true! If it were my choice, I wouldn't buy a CPU that had less than 4-cores atleast, but that's just my opinion. I know that my last machine, which was a dual core 2.13 Ghz first gen core2, was amazing, and even though it was slow when multi-tasking compared to my 6-core, it did everything else just as fast and as "smoothly" as I could expect of it. So even though I personally would shell out the extra cash for more cores, I do realize that even a dual core machine can be very fast.

Secondly let me just say that I would recommend that you stick with your current comp until the next new wave of CPUs comes out, because I know that position you're in, where you have a 4 year old computer and the new stuff sounds like it'd be fun to build, but trust me, it's no faster now than it was back then :).

Anyhow, I'm not even sure what the technical term is for "CPU hiccups", but I've been using that term for years just because that's my biggest pet peeve with bad / cheap computer builds. I assume it has everything to do with low amounts of cache, causing unwanted swapping because I rarely see workstation CPUs have those problems (which tend to have more cache). Basically, I'm sure you've experienced this, but you're doing a task and you're definitely not using 100% of the CPU and it just hangs for a split second for no apparent reason. Or even worse is when you have a 4-core system and you utilize 1 core to 100% and 3 other cores at 5% and yet your system is still basically frozen because of that 1 utilized core! Sandy Bridge seems to be really bad for these hiccups, in my experience. That's my biggest problem with my i7-2600 at work, I'll have 4 GB ram free, 3 cores un-utilized and yet I'm basically frozen when I'm utilizing 1 core to 100%. If you're running one task (ie, rendering an image) and all cores are fully utilized then you're probably never going to see any slowness or inconsistency, because you're not switching between tasks.

I notice these issues quite a bit working in the visual Fx world. I've worked on a wide range of computers, both desktops and workstations and I always note the specs of the machine that I'm working on. I often cache particles (which is single threaded) for hours at a time, and then I'll also render images (multi-threaded) for hours at a time. I do the exact same work at home on my 1090T that I do at work on the machines that I've used for work, including my current machine which is the i7. Both the i7 that I use at work and the i5-2500 that I built less than a month ago have been genuinely disappointing. An example of what I'm seriously disappointed with is this: when I'm caching particles (which is single threaded), I can't do ANYTHING!!!! ... It drives me insane! I honestly can't even browse the internet! No youtube, not even Winamp will play smoothly, it makes me wanna cry ;(. Out of curiosity, I decided to try the same thing on my last build which was the i5-2500 and that was the exact same way, maybe a tiny bit better actually, which made me feel good, and the person it's going to isn't going to care, but seriously, I was disappointed and at the same time, I was not surprised because I have noticed this trend with the successors of the core 2. They just don't seem to work quite as well in real world use.

Now, on the flip side, the 1090T that I'm typing on now is the exact opposite. There's virtually no slowdown at all when multi-tasking. I can almost play games while I'm caching .... almost :). Just to test this, I decided to cache one of these scenes I have at work and I'm typing this with no noticeable slowdown, playing winamp and switching between tasks is completely drama free, no slow down whatsoever. I even tried starting Civ IV, but that definitely didn't work haha, so I'm closing it now. On the i7, Chrome freezes on about 80% of webpages, Winamp skips and hitting Ctrl alt del takes about 5 minutes to pop-up, as opposed to about 10 seconds on the AMD. Both machines have 8 gigs of ram.

One more story on this subject was a job I did in October of last year where the company I went to needed computers badly to finish the project I was hired for. They asked me what kind of workstation I wanted and I spec'd out a machine that I wanted on newegg. It was a 24-core, 64 GB machine for $4,000. Yes you read that correctly, 24-cores and 64 gigs for $4k! To make a very long story short, they ended up ordering two of these machines, and they also ordered a 48 gig, 3.0 Ghz 12-core intel mac workstation, both of which would run windows, maya and render images on the renderfarm as well as do fluid simulations (which is multi-threaded). Well overall, after a lot of different real world usage and stress tests and a month straight of rendering and fluid sims, the AMDs were roughly 20% faster than the 12-core Intel Macs. Sure the AMDs had a bit more ram, but there was a long period of time where they were running 22 different renders on a single machine, so each core had less than 3 GB of memory per frame! Still, performance was solid and the machines were very responsive the entire time. Single threaded performance was far better on the Intels, there's no doubt about that, but all the work we were doing was multi-threaded, which balanced things out, but actually favored the AMDs a tad more. At the end of the project, I found out that the mac was actually purchased directly from Apple with all those 48 gigs (meaning that they actually paid Apple's ridiculous ram prices!) and the cost was around $12k!!!

Honestly though, we all know exactly what you mean when you say that you haven't heard anything positive about AMD... that has always been the case! It has everything to do with Intel's marketing and the public image advantage that Intel has always had since the Pentium 1. I remember when the AMD K6-2 came out, it was made out to be a joke because of its bad floating point performance, but its integer performance was on par, if not better than the Pentium II and it was actually much faster when comparing dollar for dollar... but still, the public just hated it, mostly because they loved Intel. Then fast forward a few years later and the first Athlon came out and totally obliterated the last generation PIIs in terms of floating point performance and it cost less too, but even that was hated because now it was the integer performance the people were griping about. Then there was that whole 5 year period of the Pentium 4, which was just an attrocity in terms of CPUs.... and even during those years, AMD was offering a far superior CPU for less money and even still Intel had the good public image and sells about 10x more than AMD... it was just plain sad! The P4s were proof that the public was just a bunch of sheep, because that CPU was trash... Even the IT guy that worked at the company where I built my two 24-core systems had nothing but bad things to say about AMD, yet he clearly knew just enough to have an IT job lol! After a month of seeing every other machine have issues, those magny-core systems were rock solid and totally saved our project from a slow and painful death... Yet he still said nothing good about them til the day I left (I assume he felt dumb for buying the $12k mac).
GTX 470 | 16 gigs | AMD 1090T | Win7-x64 | Maya til death!
Leiurus
Licensed Customer
Posts: 38
Joined: Thu Jan 26, 2012 3:30 am

@Weesel

I wish I could give you some useful inputs on low-end CPUs but the last time I bought this kind of hardware was more than 10 years ago and I wasn't doing any kind of 3D work at this time. Since I always acquired / work on a at least mid-range products and therefore have no experience in that field, I hope someone with more knowledge than me will be able to help you. I wish you best of luck in your studies and future career.

@Reggie

Firslty, many thanks for taking the time to give me such a detailed answer. It is highly appreciated and rich in information.

I'll try to find the time to PM you to share my thoughts and experience reagarding Intel CPUs, I don't want to hijack OP's thread.
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