bigger FSB cache or faster CPU?

in General Discussion edited January 2014
What do you think is better for heavy CAD work- a 500 Mhz CPU with 500 KB of full-speed cache or a 1 Ghz CPU with 256 KB of full-speed cache?


  • Reply 1 of 10
    eskimoeskimo Posts: 474member
    [quote]Originally posted by Randycat99:

    <strong>What do you think is better for heavy CAD work- a 500 Mhz CPU with 500 KB of full-speed cache or a 1 Ghz CPU with 256 KB of full-speed cache?</strong><hr></blockquote>

    The 1GHz CPU would almost certainly be faster. An increase in cache from 256KB to 512KB in most cases yields a performance increase of approximately 10% in most apps. 30% at the most. On the other hand you could very likely see a 100% increase in performance by doubling your CPU assuming that was the previous bottleneck and not things such as memory bandwidth, video card and so on. What CPU family are you looking at? Xeon vs. Athlon? In that case remember that there is more to a cpu than clockspeed, you will gain a further increase in performance by choosing a CPU that is faster even at the same clock speed such as an Athlon. I'm assuming you are talking about a PC since you mentioned heavy CAD work and that isn't usually done using a Macintosh.
  • Reply 2 of 10
    trowatrowa Posts: 176member
    if you are doing heavy CAD work than I would go with the 1 GHz. Although there are more things to consider than just the CPU speed and cache (ie L2/L3 cache, video card, memory). Basically the same things Eskimo outlined above. The video card is definately just as important as the CPU for 3D/CAD work.

    It's true that most heavy CAD work is done on the PC. Although the Mac does have a following with a few companies.

    Here is an example of a company that uses Macs for their CAD and VFx work

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  • Reply 3 of 10
    Thanks for the response, guys! I was beginning to think my post was being ignored for troller fodder.

    The new place I work at now (yes, I am once again employed- yet another happy story ending...) uses Xeons exclusively with the 512 KB FS L2 caches. ...But they seem to be woefully behind in keeping up with the latest clockrates. So right now I am working (well dragging by) on a 500 Mhz Xeon. So I'm toying with ideas on what I should ask for (not that I realistically could make such a request, being so new to the company). A 1 Ghz Xeon would be nice, but if push comes to shove, I could revert to plan B and maybe convince them to get a cheap 1 Ghz Pentium (but I wonder if the reduction in cache size would put me back a few steps than I had gone forward with the clockrate; we are talking long, convoluted CAD here, so I wonder if the cache could be a bigger factor than normal).

    The PC guy here seems pretty reliant on Intel and Dell (as evidenced by the machines here). I've been curious about the FPU advantages of the Athlon in CAD for some time, but I'm really not confident I could sell that idea to him. I'd really like to try one though (almost got one at my last job, but oops, they fired me before that happened). I don't know any retailers with the BTO savvy and large corporation support of Dell, so that just makes that idea that much harder to sell.

    There is one P4 system here, but I doubt I could get one being so low in the queue that I am. I'm not even sure it would even be that great for CAD, given the mediocre performance on conventional floating point operations (SSE2 support for CAD is slim to nill). My hunch is not to even touch a P4 until more cache is available, they are well above 2 Ghz (and affordable at those speeds), and they get a decent DDR SDRAM setup (or something better) figured out.

    The videocards here are not the greatest, but not bad either. Screen refreshes on large models are manageable. What I truly need is brute force processing power to speed up model rebuilds of complex assemblies (not a graphics issue at all). To boot, software screen renders and animation captures to avi are 2 other operations that need a serious boost here. So I'm thinking I need some serious floating point to speed this kind of stuff up.

    It seems pretty clear that I won't be able to get anything close to what I really need anyway (low man on the totem poll gets jack until he proves himself..), but it's an interesting topic/premise I've always wanted to bring up and get some feedback on. Maybe all this Mhz hysteria is all for nought being that L2 caches haven't similarly scaled in size (while maintaining full-processor speed parity). This is my own suspicion. A 2 Ghz processor is really great...for about as long as a 256 KB cache can keep the CPU fed with data. After that, it's wait city to access main memory (where 100's of MB of data are hanging in the balance). So that 2 Ghz processor runs like one for about a 100 msec (speaking about heavy CAD work, still), then drops to an effective 500 Mhz or so for the next 15 minutes as it works primarly with data from main memory. This is my crazy theory, of course. It just feels that way when these "high-Mhz" computers hit any kind of task that pegs the CPU for longer than a blink. It's like they hit a wall, and all of a sudden you might as well be on some old Pentium II. What I would really would like to try is some hypothetical 2 Ghz computer with a truly ballsy 100 MB of full-speed cache. It's a monetary impossibility, but I think that is what we (as in we severly, heavy computer users) really need to utilize the core speed of these high speed computers (unless you happen to be in some quaint little streaming data kind of scenario, but even then you need a robust main memory system that can stream fast). Otherwise, it's all about as meaningful as the peak rating on a car amplifier. So am I on crack?

    Edit: My ending provocative remark- I don't care if Intel has a 10 Ghz CPU in the books, if they sell it to us with a miniscule 256 KB cache, is this really an impressive thing?

    The subtext: I've been running this slow-a$$ computer to within an inch of its life for the past week on stuff it has no business running, and I got to vent a little today! ...But I still invite serious comments to my post.

    [ 02-25-2002: Message edited by: Randycat99 ]

    [ 02-25-2002: Message edited by: Randycat99 ]</p>
  • Reply 4 of 10
    Randycat, you might find the workstation series of articles at useful. They examine various components effects on professional applications such as high end 3D and CAD.

    <a href=""; target="_blank"></a>;

    <a href=""; target="_blank"></a>;

    <a href=""; target="_blank"></a>;

    <a href=""; target="_blank">Here</a> you can see a single Athlon 1.4GHz Tbird beatin up on a Dual Xeon 1.7GHz in AutoCAD. For raw x87 performance the Athlon can't be beaten by any Pentium processor.

    <a href=""; target="_blank">This link</a> shows the effects of various high end video cards on CAD applications and benchmarks.

    Keep in mind these benchmarks are a few months old. Intel today introduced their new "Prestonia" Xeons (basically a P4 northwood with symmetric multi-threading enabled) and the Athlon MP is up to 1900+ (1.6GHz) and Athlon XP is at 2000+ (1.67GHz)
  • Reply 5 of 10
    Thanks for your honest response, Eskimo. I'll check out your links. It wouldn't surprise me to see an Athlon to do so well against a Xeon, but the major puzzle piece missing is who sells a complete Athlon system with the same sense of product guarantee and support such as you would perceive from making a Dell purchase? That's the critical leap of information I have to sell, otherwise I can ask for an Athlon all day and the systems administrator will say, "Yeah, that's nice. Move along."
  • Reply 6 of 10
    eskimoeskimo Posts: 474member
    Major OEM support for AMD is one of their weak points at the moment. But there are quite a few reliable "Tier 2" manufacturers out there. I personally do not play a part in IT aquisitions so I can't vouch for any of the companies personally but have heard only good things about the follwoing:

    <a href=""; target="_blank"></a>;

    <a href=""; target="_blank"></a>;

    <a href=" ddr.asp&quot; target="_blank"> ddr.asp&lt;/a&gt;

    If you do want to go Tier 1 probally your best choice for AMD based products is <a href=""; target="_blank"></a>
  • Reply 7 of 10
    Thanks for the extra info. If I see a window of opportunity, I will definitely suggest those sites.
  • Reply 8 of 10
    randycat99randycat99 Posts: 1,919member
    The head IT guy here says there is a good reason there are no Tier 1 vendors that offer any Athlon setups. He alludes that, as Tier 1 vendors, their products must feature corporate level reliability, and that such a product containing an Athlon with related componentry just cannot be made with such reliability (as a workstation level Dell, for example). Do you think this is true (Eskimo, anybody?), or just reactionary thinking?
  • Reply 9 of 10
    stimulistimuli Posts: 564member
    Reactionary thinking. IT guys fear change. Just try asking them to switch to linux.
  • Reply 10 of 10
    eskimoeskimo Posts: 474member
    Somewhat reactionary. The truth is there are few Tier 1 companies that remain that produce business oriented computers, the majority buy from Dell now of days. Support for the AMD platform requires an additional investment in resources by those Tier 1 manufacturers, something that during lean times such as this most are not willing to do. Thus they simply don't offer AMD systems in their business line ups. MicronPC is still considered a Tier1 OEM and offers AMD based systems.

    For the year 2001 AMD had a 37% market share for small business, 28% share for medium sized business, 17% share for education, and 32% share for government workstations. You don't achieve share such as that without reliable products. It is just as possible to build a stable AMD platform as an Intel one, it just requires some careful decision making on the part of the integrator.
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