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hjh
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Joined: 20 Jul 2004
Posts: 37
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 Posted: Tue Nov 16, 2004 6:03 am Post subject: Comments on hardware specs for amd64 system? |
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I would appreciate any wise comments on the following system if people are willing.
dual opteron 246
tyan thunder k8w
4x corsair pc3200 512Mb registered DDR SDRAM
550W Antec True Power ATX12V 24 pin PSU
Antec PlusView 1000AMG case
Aopen GeForce FX-5700 128MB 8xAGP video adaptor
Seagate 120GB SATA, 7200rpm, 8MB cache
.....and other less important bits like optical drives, and peripherals
The system will be running Gentoo 64/32 bit and will spend a bit of time compiling here and there though this will not be a primary function.
Main uses will be the running of scientific applications, many of which are multiprocessor capable and others will be developed on this system in time.
I did consider running RAID 0 but in the end was nervous about doubling the points of failure in the hard drive department! Also, the budget is limited. I'm sure the system will be more than adequate but I am keen to hear of any gotchas or perhaps stupid choices I may have made.
Thanks in advance
J. |
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tgnb
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Joined: 16 Apr 2002
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Location: New York, NY
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| Posted: Tue Nov 16, 2004 12:19 pm Post subject: |
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What do you need in the thunder k8w that the tiger k8w doesn't have?
Also, if you're worried about doubling the points of failure why not make it a RAID 1 system? And why do you need a GeForce FX-5700 for a system thats running mostly scientific apps? Do you intend to use the same box for gaming or are those apps also 3d intensive? |
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tarzan420
Tux's lil' helper
Joined: 05 Jul 2003
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Location: Fairbanks AK
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| Posted: Tue Nov 16, 2004 6:57 pm Post subject: |
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sounds like it shouldn't be a problem, it's like a high end version of my box (2x242, MSI Master2Far, 2x512MB Transcend, Geforce FX 5700, SATA...)
FX5700 should do pretty much everything you need for any vizualization - it plays doom3 quite nicely on my box.
enjoy the quick compile times, don't forget to put -j2 in your MAKEFLAGS.
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The power of Unix coupled with a pleasing interface and scores of usable desktop applications is a disgusting perversion of everything Unix stands for. |
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lavish
Bodhisattva
Joined: 13 Sep 2004
Posts: 4296
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| Posted: Tue Nov 16, 2004 7:05 pm Post subject: |
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| tarzan420 wrote: | sounds like it shouldn't be a problem, it's like a high end version of my box (2x242, MSI Master2Far, 2x512MB Transcend, Geforce FX 5700, SATA...)
FX5700 should do pretty much everything you need for any vizualization - it plays doom3 quite nicely on my box.
enjoy the quick compile times, don't forget to put -j2 in your MAKEFLAGS. |
j2? j3 for a dual opteron.... and not MAKEFLAGS, but MAKEOPTS 
so...
makeopts="-j3" , oky?
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get sirius
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Joined: 27 Apr 2002
Posts: 316
Location: Madison, WI
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| Posted: Tue Nov 16, 2004 11:17 pm Post subject: |
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Well, for starters, I recommend the LianLi V1200 case for far superior ventilation with fewer fans - your whole system WILL run cooler. And considering my recent experience with Antec power supplies ....  Get in touch with PC Power and Cooling and check out their power supplies; they're expensive (around $200), but there are none better! Corsair is a sound memory choice; I'm using 4x512 sticks of Corsair's extra-low-latency PC3200 (lower latency does make a difference!). People have reported problems with FX5700 cards with the K8W board - I'm using the FX5700Ultra and have had no problems on my Thunder K8W.
tgnb: The differences between the Thunder K8W and the Tiger K8W are vast and, taken all together, add up to a much more performance-oriented motherboard!  |
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tgnb
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Joined: 16 Apr 2002
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Location: New York, NY
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| Posted: Wed Nov 17, 2004 2:08 am Post subject: |
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| get sirius wrote: | | tgnb: The differences between the Thunder K8W and the Tiger K8W are vast and, taken all together, add up to a much more performance-oriented motherboard! |
I know that there are differences but i wouldnt exactly call them "vast". Anyway, i asked him not what the differences are, but what OF those differences he really thinks he needs. |
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Krischi
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Joined: 07 Feb 2004
Posts: 16
Location: Washington DC
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| Posted: Wed Nov 17, 2004 2:44 am Post subject: |
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| tgnb wrote: | | I know that there are differences but i wouldnt exactly call them "vast". Anyway, i asked him not what the differences are, but what OF those differences he really thinks he needs. |
The dedicated memory bus for each CPU in the Thunder K8W versus the shared memory bus in the Tiger is a pretty big difference in my book. Scientific applications are notorious for being limited by memory bandwidth. Of course, it depends on the specific application in question, but with any serious crunching of images or matrices that exceed the L2 cache size, odds are that you need all the bandwidth that you can get. |
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get sirius
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| Posted: Wed Nov 17, 2004 2:58 am Post subject: |
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| And.... And.... And the PCI-X slots really up the ante with large transfers to/from the hard drives. And the gigabitE on the Thunder K8W runs through one of the 66-bit 133MHz PCI-X slots instead of being limited to the 32-bit 33MHz std PCI slot (which helps with large xfers between networked machines. |
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tgnb
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tgnb
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Joined: 16 Apr 2002
Posts: 208
Location: New York, NY
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| Posted: Wed Nov 17, 2004 3:03 am Post subject: |
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| get sirius wrote: | | And.... And.... And the PCI-X slots really up the ante with large transfers to/from the hard drives. And the gigabitE on the Thunder K8W runs through one of the 66-bit 133MHz PCI-X slots instead of being limited to the 32-bit 33MHz std PCI slot (which helps with large xfers between networked machines. |
I'm getting a free hardware lesson I love it. How does the PCI-X slots up the ante with large transfers to/from the harddrives? I thought the drives are connected to the SATA controllers? |
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Krischi
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Joined: 07 Feb 2004
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Location: Washington DC
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| Posted: Wed Nov 17, 2004 3:49 am Post subject: |
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| tgnb wrote: | | Maybe I need some extra education but the Tiger has the same " 128-bit DDR dual-channel memory controller" as the Thunder. Is the memory bus something different? Where in the spec can i find this? |
Ok, first of all, this is a majorly complex subject, and I have to simplify a lot. However, at the same time, this is one of the coolest things about the Opteron design. The key difference, kind of hidden in the specs, is (emphasis mine):
"Memory:
Eight 184-pin 2.5-Volt DDR DIMM sockets
- Four per CPU"
In a nutshell, the Xeon, as well as older Athlon MP designs, forced the processors all to share the same memory bus. As a consequence, in memory intensive applications the CPUs would compete for memory bandwidth and step on one another's toes, so to speak. For instance, with the dual-channel memory controller in the Opterons and PC3200 DDR-SDRAM, you are limited to a maximum theoretical bandwidth of 6.4 GB/s. If both CPUs intensively compete for this bandwidth, at best, they end up with only half of this theoretical share. In some scientific applications, in particular, this limitation can make adding a second CPU almost worthless, because a single CPU already crunches the numbers fast enough to saturate the memory bus.
The Opterons have their memory controller integrated on the chip - so each CPU has its own, separate memory controller. This means that each CPU can work with its own RAM, without competition from the other CPUs. So, instead of sharing 6.4 GB/s across two CPUs, you end up with a total combined memory bandwidth of 12.8 GB/s for two CPUs. For a low-cost workstation, this is an absolutely staggering number. Nothing else in this price class comes even close. This design also scales very well when you add more CPUs, since each CPU brings its own memory controller on board.
Still, the CPUs do need to share data, which is where AMD's Hyper Transport technology comes in (google for more info). The Opterons use it, among other things, to communicate with the other CPUs and to access another CPU's memory. Only in this case you will see competition among the CPUs for memory bandwidth.
With this excursion in mind, it's time to come back to the difference between the Tiger and the Thunder mainboards. Quite simply, the Tiger has support for only one memory controller, so the CPUs end up sharing the memory bus. In contrast, the Thunder supports two memory controllers, so each CPU can have its own, dedicated RAM.
With suitable applications and NUMA support in the OS (e.g. Linux >= 2.6), to distinguish between local (the CPU's own) and remote (another CPU's memory), this difference can result in much better throughput. Let me stress, though, that this is an advantage for very specific application profiles. On an average home or office workstation, it is unlikely to make a large difference. |
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tgnb
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| Posted: Wed Nov 17, 2004 5:16 pm Post subject: |
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Krischi:
I've read your answer a few times and I believe I found a flaw in your explanation:
You correctly state:
| Krischi wrote: | | The Opterons have their memory controller integrated on the chip - so each CPU has its own, separate memory controller. |
Then further down in your answer you say incorrectly:
| Krischi wrote: | | Quite simply, the Tiger has support for only one memory controller, so the CPUs end up sharing the memory bus. In contrast, the Thunder supports two memory controllers, so each CPU can have its own, dedicated RAM. |
As you said, the memory controller is ON the chip and not the board and both the Tiger K8W and the Thunder K8W support 2 Opteron chips. Therefore both the Tiger and the Thunder have 2 memory controllers, 1 for each Opteron Chip.
Because this is not 100% clear in the specs, i called Tyan Technical support and verified this.
The Tyan Tech support person confirmed to me that both the Tiger K8W as well as the Thunder K8W have no difference in memory bus or bandwidth. The ONLY difference is that the Thunder K8W supports 4 memory chips per CPU and the Tiger only supports 2 per CPU. But on both boards, each CPU has its own memory bus.
By the way, as per the suggestion from a couple of the devs in the gentoo-amd64 IRC channel i have MAKEOPTS="-j4"  |
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Krischi
n00b
Joined: 07 Feb 2004
Posts: 16
Location: Washington DC
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| Posted: Wed Nov 17, 2004 5:55 pm Post subject: |
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| Quote: | | As you said, the memory controller is ON the chip and not the board and both the Tiger K8W and the Thunder K8W support 2 Opteron chips. Therefore both the Tiger and the Thunder have 2 memory controllers, 1 for each Opteron Chip. |
The problem is that each memory controller needs to be hooked up to the memory banks. Every review article that I have seen on the Tyan Tiger states that only the first CPU's controller accesses the memory banks. The second CPU has to go through the first one.
| Quote: |
The Tyan Tech support person confirmed to me that both the Tiger K8W as well as the Thunder K8W have no difference in memory bus or bandwidth. The ONLY difference is that the Thunder K8W supports 4 memory chips per CPU and the Tiger only supports 2 per CPU. But on both boards, each CPU has its own memory bus.
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With all due respect, it seems that the tech rep has told you bunk. But you do not have to take my word for it. If you go the datasheet pages for the Tiger and Thunder K8W boards, on each respective page 2, you will find the block diagram for the board. These diagrams show clearly that the CPUs on the Thunder K8W have each their own DIMM banks, whereas on the Tiger K8W, all accesses go through the H1 CPU.
So, it is the datasheet versus the tech rep. Given the overall quality of tech support in the industry, I tend to believe the datasheet, at least for the time being. |
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tgnb
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Joined: 16 Apr 2002
Posts: 208
Location: New York, NY
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| Posted: Wed Nov 17, 2004 6:31 pm Post subject: |
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Krishi: I checked out the block diagram on the datasheets, and a crispier version of it in the manuals. After reviewing this I once again called back Tyan tech support and the tech i spoke to this time confirmed that the memory bank in the Tiger is shared while each of the memory banks in the Thunder are dedicated to the processor.
So to clear everything up, while both boards have processors with integrated memory controllers, the bus over which these memory controllers communicate with the memory itself is shared on the Tiger, whereas it is dedicated for the Thunder.
I see the difference now Thanks |
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get sirius
Guru
Joined: 27 Apr 2002
Posts: 316
Location: Madison, WI
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| Posted: Wed Nov 17, 2004 11:24 pm Post subject: |
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| Yep, the drives are connected to the SATA controllers, and if the controllers used are integral to the motherboard they go through the standard 32-bit 33MHz PCI bus. However, the gentleman who initially asked the questions wanted to use an add-on controller card, most of which can take advantage of the 64-bit 66MHz PCI-X bus, which offers four times the throughput of a PCI bus. |
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hjh
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Joined: 20 Jul 2004
Posts: 37
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| Posted: Thu Nov 18, 2004 2:37 am Post subject: |
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Some comforting replies in here and some good discussion, thankyou all.
w.r.t choosing the Thunder over the Tiger: I am thinking a little about the future here and the memory expandability may well be an issue. From the simple perspective of longevity it influences me. Also, rightly or wrongly, I was influenced by an earlier review I read comparing the MSI K8T, Thunder and Tiger. (sorry can't remember the link)
Re the video card: Molecular visualisations and real-time rendering of large systems of many atoms, some with fancy primitives added for highlighting particular properties, all adds up to a fair drain on resources. If I can spin an assembly of 100 overlayed molecules around in real time and focus in on specifics without having to wait for chunky graphics then it's worthwhile. I am currently using a 32MB GeForce4 with some of the OpenGL apps that I use for the visualisations. It does pretty well but chunks when I get up to tens of molecules or particularly large systems.
Of course I could no doubt live happily enough with some lower specs here and there but when you are spending someone else's money why skimp?! |
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Krischi
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Joined: 07 Feb 2004
Posts: 16
Location: Washington DC
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| Posted: Thu Nov 18, 2004 2:25 pm Post subject: |
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| hjh wrote: |
Re the video card: Molecular visualisations and real-time rendering of large systems of many atoms, some with fancy primitives added for highlighting particular properties, all adds up to a fair drain on resources. If I can spin an assembly of 100 overlayed molecules around in real time and focus in on specifics without having to wait for chunky graphics then it's worthwhile. I am currently using a 32MB GeForce4 with some of the OpenGL apps that I use for the visualisations. It does pretty well but chunks when I get up to tens of molecules or particularly large systems. |
Okay, while we are talking about skimping: Have you considered a card from the NVidia Quadro line instead of the GeForce line, assuming that your budget allows for it? Both lines have excellent support from the NVidia binary drivers under Linux, but the Quadro is more geared toward scientific and professional applications. It has been a while since I did a direct comparison between these two lines, but back then the GeForces were rather slow at operations that were not geared toward games. I don't know how much this applies to your visualization needs, but if you can find someone with the hardware, I would run a visualization comparison between these two lines. |
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hjh
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Joined: 20 Jul 2004
Posts: 37
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| Posted: Fri Nov 19, 2004 12:14 am Post subject: |
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| No I hadn't looked at the Quadro cards. I will have a look and see what I can turn up. Sadly there is not a bottomless pit of money to throw at this system...more's the pity! |
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Gentoo on AMD64
