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Old 04-06-2008, 11:23 AM   #16
H_TeXMeX_H
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Well, the CPU frequency or clock rate is the approximate number of instructions per second a processor can do. If you have 4 cores each running at 2.4 GHz and you use all of them on running a single program, and this program is designed perfectly (along with the kernel, which we all know is also perfect), then the theoretical maximum apparent CPU clock rate would indeed be 4 x 2.4 GHz = 9.6 GHz for this program. BUT, as you may guess, things are never perfect, and even the best designed program may never achieve this for numerous reasons. Don't ask me to name them, ask jay73, he may know more of them. Also, remember that it's not a good idea to compare 'GHz' between processors, it doesn't work well even within the same manufacturer or same series of processor.
 
Old 04-06-2008, 11:40 AM   #17
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Thanks, H_TeXMeX_H!

I checked some benchmarks and it appears that the Intel Core 2 Duo E8400 comes out as the better alternative in most of the tests:

http://www23.tomshardware.com/cpu_2007.html
 
Old 04-06-2008, 11:54 AM   #18
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Unfortunately those benchmarks are run on windows. The number of applications that are multi threaded in windows is limited (relative to linux). So you have to be careful comparing a single threaded app on a single core cpu and a multi threaded app on a multi core cpu. A single threaded app run on a multicore cpu will run slower than it would on a single core cpu.
 
Old 04-06-2008, 12:15 PM   #19
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As H_TexMex_H suggests, those are "only" theoretical values (but not totally meaningless either). There are quite a few bottlenecks in hardware and software that prevent a system from achieving the maximum.
One of the traditional bottlenecks has been hard drives. A CPU may be faster at executing its instructions than another one but if it has to wait for data, it's simply not doing much half of the time. That is why a core 2 duo in combination with a Raptor drive (10000RPM) is every bit as fast at rendering as a quad core with a 7200rpm SATA drive. But even at 10000RPM, there is no way that a drive could keep up with today's CPUs. Of course, quad + raptor will still be faster than dual + raptor.
RAM, motherboard chipset, GPU, cache - all of those can become bottlenecks too. In fact, if your software does hardware rendering, you will benefit more from getting a better video card than from choosing a quad core over a dual core (as video cards tend to process data a lot faster than CPUs).
All else being equal , the quad should render faster than the dual core: it may be slower but then each core gets only half the work to do so it does come out the faster one in the end. It should but that again depends on your software. If one thread has to wait on other ones, having more cores/threads also means more waiting. But rendering is one of the areas where threads tend to run in parallel so that shouldn't be an issue.
Sometimes the difference is noticeable, other times it is not at all. But it will never be a literal 6Ghz versus a literal 9.6Ghz, which would suggest that the quad is 60% faster under all or most conditions.
I had a look at the benchmarks you posted. They seem to confirm my suggestions. But one thing you should keep in mind is that moving to a quad core from a dual core does not offer the same performance boost as moving from single to dual core. I generally would not recommend anyone who already has a good dual core to upgrade to a quad. The performance gain is just not good enough. Of course, if you are upgrading from a single core, you are in different situation. You'll get a computer that runs faster no matter which one you prefer.

Last edited by jay73; 04-06-2008 at 12:28 PM.
 
Old 04-06-2008, 12:31 PM   #20
MasterOfTheWind
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Thank you lazlow and jay73.

I don't know if it's too much to ask but is there anyone willing to comment or suggest changes to the following rig setup:
Code:
*Cooler Master Centurion 534
*Corsair Powersupply 550W Bulk, black, ATX/EPS, 120mm fan, 4xSATA, SLI
*Asus P5K, P35, Socket-775, DDR2, ATX, GbLAN, PCI-Ex16
*Intel Core™ 2 Duo E8400 3.0GHz, Socket LGA775, 6MB, 1333Mhz
*Akasa AK-956SF CPU fan, Socket 775
*Crucial DDR2 PC6400 4096MB CL6, Kit w/two matched DDR2 PC6400 2GB CL6
*[2x] Seagate Barracuda 7200.10 250GB SATA2 16MB 7200RPM
*XFX GeForce 8800GT 600M 512MB GDDR3, PCI-Express 2.0, 2xDVI,8-layer black PCB
This will be a dual screen setup and I am planning to use it for:

most of the time:
*office
*internet browsing
*watching movies
*listening to music

occasionally:
*programming
*3d modelling and rendering / raytracing
*gaming
*virtualization (qemu...)
 
Old 04-06-2008, 02:00 PM   #21
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Well, for one thing that I notice right away, that power supply may be inadequate ... I have a similar setup with a Quad Core, less RAM, and only 1 HDD, and 550 W was not enough, the power supply kept overheating, it smelled like burning, I had to take it back and get a 620 W one. There is a chance the original power supply was defectous, but I doubt it. So, I say get at least 600 W, or if you have problems with the power supply then upgrade it.
 
Old 04-06-2008, 02:08 PM   #22
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Oh, ok, thanks. Let's then say "Corsair Powersupply 650W Black, ATX/EPS, 120mm Fan, 8xSATA, SLI"

PS. Forgot to mention: I'm planning on overclocking the CPU at may be somewhere around 3.3-3.6 GHz depending on how far it can go without becoming unstable.
 
Old 04-06-2008, 02:17 PM   #23
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A CL (cass latency) of 6 is a bit high for 800Mhz DDR2. RAM is more responsive as the latency decreases.

Be careful with the promised RAID support. This motherboard has an ICH9 chipset which does NOT support RAID. The only type of RAID support is external RAID through the JMicron controller. Which suggests another issue: the JMicron controller is working perfectly fine for me but I know that not everyone has had the same experience. Distros that use the sr module will work fine, though. You may have to put in some extra work if you use one of the roll-your-own distros.

One suggestion about the case: think ahead. I have recently had to buy a new one because I believed that I'd never have more hard drives than my case could house. Wrong guess...

Over-clocking implies extra power consumption. Bear in mind that there is a lot of difference between PSUs. Seasonic, Antec and a some others tend to be a bit more expensive but it is usually worht it (unless you get the cheapest ones they have on offer, of course). Cheaper / generic PSUs tends to cut costs by saving on 12V rails, that is why a 550W quality PSU is generally a lot more reliable than 700 or 800W generic PSUs.

If you like a fast OS, consider getting a WD Raptor and a 7200RPM II for storage rather than two 7200RPM drives.

Last edited by jay73; 04-06-2008 at 02:31 PM.
 
Old 04-06-2008, 02:27 PM   #24
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Thank you for your suggestions. Some questions:

1) I do not know whether I will use RAID, but what exactly is "external" RAID?

2) What if I choose "Corsair TWIN2X 6400 DDR2, 4096MB CL5, Kit w/two matched CM2X2048-6400 Dimm's"? They are CL5 and cost less (for whatever reason).

Quote:
that is why a 550W quality PSU is generally a lot more reliable than 700 or 800W generic PSUs.
3) What do you mean by more reliable?
 
Old 04-06-2008, 02:49 PM   #25
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1) RAID is a technique to combine hard drives. A RAID1, for example, will write to/ read from two hard drives at once, resulting in higher IO performance (and increased risks: if one drive dies, the data on the other one is lost two because the data were split up). There are also types of RAID that automatically back up everything you write to one drive to one or more other ones, which is not faster but more reliable.
External RAID is a RAID involving an internal drive and an external one. In short, useful only if you have one of those external drives. This is hugely inconvenient if you want to use RAID1: you would have to leave your external drive connected all the time...

2)Corsair is one of the best RAM manufacturers around. They tend to be more expensive but now that DDR2 in general has become dirt cheap, that's not much of an issue anymore. Excellent customer service, also. They immediately sent me a replacement when my local shop wouldn't help me.

3) It is all about the way that the 550W are distributed among the rails. Cheaper PSUs tend to cut on the more expensive 12V type of rail and they use to rely more heavily on 5V ones as a substitute - but the latter are more prone to short-circuits. So to the eye, it's 550W too, only your 550W is a lot more likely to end in a burned-out PSU (and sometimes short-circuited RAM, mobo, CPU, ...) because the materials are inferior. PSUs are the last component you would want to save on, really.

Last edited by jay73; 04-06-2008 at 02:51 PM.
 
Old 04-06-2008, 03:05 PM   #26
MasterOfTheWind
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But is the 650W-PSU I suggested (Corsair Powersupply 650W Black, ATX/EPS, 120mm Fan, 8xSATA, SLI) to be considered one of the cheap/low-quality type you describe?

And one more question: is thermal grease something that is usually included with the CPU?

Damn this rig is getting more expensive by the minute May be I will have to wait till summer after all...
 
Old 04-06-2008, 03:10 PM   #27
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Jay

I am pretty sure what you describe as Raid1 is really Raid0. Raid0 is faster R/W and all the space of the drives(no backup). Raid1 is normal R/W speed but mirrored(backed up) so you only get 1/2 the drive space.
 
Old 04-06-2008, 06:45 PM   #28
jay73
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@lazlow

Oops, yes, that should have been RAID0 or RAID0+1 (which combines 0 and 1).

@MasterOfTheWind

Corsair is one of the better PSU manufacturers so that should be a safe choice. Do you really need 650W? My Antec Sonata III case (come with a 550W PSU) runs all of this without a problem:
- Core 2 Duo
- 1CDRW
- 2xDVDRW
- 4xSATA II
- Nvidia 7600GST
- Creative Sound card
- Sata controller card
- ASUS mobo
- CPU fan + 2 case fans
Now look at the specs of that 650 W PSU:
- SLI support
- 8 x SATA
That would appear to have more punch than you really need (at this time, that is - if you intend to upgrade or add more components at some point in the future, it is another story, of course).

As for the thermal grease, that would depend. Are you going for the boxed or the tray version? (The boxed version of the CPU comes with a fan and thermal grease pre-applied to the heatsink, the tray version is just the CPU). C2Ds run quite cool so the boxed version should be fine but if you are going to overclock, it may be better to get the tray version and separate fan unless you don't mind removing the stock paste and replacing it with your own. Thermal paste may be included with a separate CPU fan/heatsink, you'd need to check.

Last edited by jay73; 04-06-2008 at 06:47 PM.
 
Old 04-06-2008, 09:13 PM   #29
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A good low noise to almost noiseless power supply brand is Seasonic. The two power supply brands that I suggest are Seasonic and Enermax. Do not believe in the multi-volt rails for 12 volts and 5 volts. Yes more rails do provide more redundancy if one fails to deliver the others will take up the slack. The complexity of making such device increases costs.

Seagate is OK, but they get very, very hot. Also they are not a good brand because very picky on the quality of power that it uses and has a history of problems with their SATA hard drives in Linux. I suggest either Hitachi or Western Digital. Western Digital has hard drives (I think GP series) that can use either 5400 RPM or 7200 RPM. The 5400 RPM is good to reduce noise and reduce power consumption at a cost of lower sustain throughput. The 7200 is for high sustain throughput at a cost of high noise and high power consumption. If you want low latency and low noise, I suggest a SSD with ECC and Western Digital GP hard drives set at 5400 RPM. Use the hard drive for logs and tmp. Then use SSD for program loading.

Corsair may have the reputable to be the best memory manufactures for all time, but this is not true. Actually the best through the years is Micron and its store Crucial. A high performance memory manufacture is OCZ.

Linux does not support all features of Creative Labs cards, so why buy them and they are costly. I suggest sound cards with VIA ICE1724 for the best sound quality. Also cards with C-Media CMI8788/CMI8787 DSP chip can also work in Linux, but with limited support. I only have a card based on VIA ICE1724, so I can not tell you how well the CMI8788 chips is supported in Linux.

If you are going RAID go for hardware solutions. A good hardware RAID brand is 3ware. I strongly recommend away from controllers such as Silicon Image, Promise, Marvel/Yukon, JMicron.

ASUS motherboards are over price for the quality that they provide. Gigabyte and Abit are alternatives that are cheap. They have the same quality as ASUS. Other brands that you could use DFI and MSI.


Back to the question. Which processor will be the fastest. This is hard to figure out because each program handles different data and provides different loads on the processor. The following is what I think.

Processor 1 will be good for multi-threaded and running multiple programs at once, but the FSB might be the bottleneck when handling large amounts of data. The larger cache will keep the four cores loaded with data before resorting main memory.

Processor 2 will be very fast processing large amounts of data and handling two PCIe X16 cards to their full capacity. It will lack in running multiple processes or multi-threads.

I suggest Processor 1 since you will be using multiple programs at once, but you may not mind too much of a slower performance while render graphics or compile programs. Games might suffer when using SLI because of the FSB bottleneck.

Tray version? There is no such thing. They are called OEM which contains the processor with out the heatsink. The box is retail. Retail version uses thermal pad not thermal grease.
 
Old 04-06-2008, 10:23 PM   #30
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Jay,

Here is one article I found. http://www.internetnews.com/bus-news...le.php/3668551 This isn't what I read, but it's very similar. I can't remember the magazine I first read it in, but it was a reputable one.

Isn't the the SOP to offer new technology on high-end servers and then it eventually gets down to the average Joe?

Brandon

edit: Sorry for taking me so long to get back. I lost track of this thread, and I honestly didn't think it would take off like it did. People really are passionate about their processors, lol.
 
  


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