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Designing new rig, need help on fsb's and cpu's, $ ok

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June 11, 2008 5:32:49 AM

I am designing my first rig.
So far I am looking at the Q9550, a GTX9800, 8 Gig Ram DDR2 (800 or 1333 mhz I am not sure yet which), Vista 64...

My real question here is about the FSB attached to the mobo - I understand that most FSB's these days are 64 bit buswidth (right??), I am wondering if anyone knows of mobo's that are FSB of 128 bit budswith and also if does anyone know if my Q9550 cpu would be compatible with / be able to make use of a mobo with a 128 bit FSB?

(The Q9550 has 1333mhz for FSB in the specs).

I figure I have 8gig ram so I want to make the exchange between the ram and cpu as accomodating as possible. This begs the next question which is what mhz for the DDR2, 800 or 1333??

Also in terms of backside buses, are there mobo's that have bigger budswidth for those aswell as the FSB buswidth being 128 bit etc? Am trying to completely avoid bottlenecks in data exchange here, please offer a suggestion or comment (am really stumped here)!

More about : designing rig fsb cpu

June 11, 2008 5:58:19 AM

forgot to say that I'm not fussed about the cost (using the Q9550 as the CPU) ie. I want the optimal ram, mobo setup to cater for that cpu and it is really hard trying to decide!
a c 203 à CPUs
June 11, 2008 6:23:45 AM

Using the Q9550 as your CPU limits you to socket 775 motherboards with all the hardware limitations that go along with the PC class of computers.

The backside bus is wholly contained inside the CPU die and has nothing to do with the motherboard.
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June 11, 2008 7:13:01 AM

Thanks WR2, what would be the best 775 socket mobo adn ram configuration then? and can you get 128 bit fsb's on 775 socket mobo's? when you say hware limitation what do you mean ie. do you mean my cpu wont interface well with a 128 bit fsb or that i cant get a 128 bit fsb on a 775 mobo etc?
a c 203 à CPUs
June 11, 2008 7:20:44 AM

What is your overclocking target with the Q9550?
128bit FSB? Are you trying to build a scientific workstation on the cheap?
June 11, 2008 9:44:17 AM

ha yeah i guess... im not trying to overclock i am trying to build a stock operated system (ie. one that i dont have to manipulate) that is going to totally (or as best possible) avoid bottlenecks between cpu and ram. i dont care about cost of ram or cost of mothreboard as long as the two are faciliting the purpose (ie. not future upgrades or ocing, just kick ass load times/ multitaksing using a Q9550) - i don't think it's that complicated really, just need someone who knows what they're on about to give me an ideal ram/ motherboard scenario for my Q9550, is that so hard???
June 11, 2008 9:45:43 AM

strike that... ideal ram/ motherboard featuring ideal fsb capability in terms of buswidth
June 11, 2008 9:56:11 AM

single channel is 64 bit. Pretty much all motherboards have dual channel memory controller so if You put ram in pairs and use dual channel it is 128 bit wide. At least that is what I understand, might be wrong.
June 11, 2008 10:04:11 AM

Yep found confirmation on wikipedia-
Dual-channel architecture describes a technology that doubles data throughput from RAM to the memory controller. Dual-channel-enabled memory controllers utilize two 64-bit data channels, resulting in a total bandwidth of 128-bits, to move data from RAM to the CPU.
http://en.wikipedia.org/wiki/Dual-channel_architecture

June 11, 2008 10:54:31 AM

clap clap clap,
What about the best ram configuration
ie. 4 gig vs. 8 gig, 667 vs 800 vs 1333mhz, DDR2 vs. DDR3,
(remember cost of mobo and ram are of no consideration based on the Q9550 as CPU platform)
we're almost there now...
June 11, 2008 10:56:59 AM

ainairsseems (thanks for your comments so far, your two notches above 95% of the people on here in my book)
a c 203 à CPUs
June 11, 2008 2:12:00 PM

I've read some of your other posts and you seem to be obsessing about a 128bit FSB for some reason.
Don't fool yourself into thinking a RAM dual channel 64bit FSB is actually a 128bit FSB. It' not. You have to think about the CPU side of the bus as well [:wr2:5]

Also you appear to be confused about FSB bandwidth's function in providing "kick ass load times/ multitaksing". That may be why you seem to be confusing others around here.

All 1333Mhz CPUs have a FSB bandwidth of 10666 MB/s. Two cores or four cores - its all 10666 MB/s.
The 2.5Ghz Q9300 and 3.0Ghz QX9650 all have the same FSB bandwidth and yet the QX9650 "kicks ass" faster?
FSB bandwidth is a function of the FSB speed. More speed=more bandwidth.
To increase the bandwidth (which you appear to be asking when you say "avoid bottlenecks in data exchange") you need to increase the FSB speed. That's called overclocking. Besides generating "wider" bandwidth a side benefit is that tasks get completed faster (as in kicking ass). Ok, actually its the main benefit and the higher bandwidth is just a bonus.

For example if you overclock the Q9300 to 3Ghz you'd raise the FSB to 400Mhz (1600Mhz quad pumped).
400*4*8=12800 MB/s of FSB bandwidth. Mmmmmmmmm! More bandwidth! Faster loading, execution and multi-tasking (but most of the increase not provided by the higher bandwidth).

To find optimum RAM? How to match the CPU bandwidth with RAM bandwidth? Have you ever wondered why RAM has TWO names?
As in DDR2 667 PC2 5400, DDR2 800 PC2 6400, DDR2 1066 PC2 8500 and DDR3 1333 PC3 10666?
The DDR part indicates data transfers per second (in millions); 677 million data transfers, etc.
The PC part indicates single channel bandwidth - as in PC2 5400=5400 Mb/s, PC2 6400=6400 Mb/s
Or PC3 10666 DDR3 1333? PC3 12800 DDR3 1600? Notice anything familiar? 1333/10666 & 1600/12800?

So what happens if you don't use optimum RAM? Not too much changes. Say you're using DDR2 800 PC2 6400 RAM?
The actual performance is very close - only a few percentage points difference which is why so many people recommend non-optimum RAM. A Q9300 1333Mhz FSB with DDR3 1333 PC3 10666 RAM running at 2.5Ghz will get its butt kicked soundly by a 3.0Ghz Q9300 1600FSB with DDR2 800 PC2 6400 RAM. Same principal applies to all CPUs.

2GB vs 4GB vs 8GB; The RAM's primary purpose is to to keep the L2 cache filled with data and instructions (as the L2 cache keeps the L1 cache filled with data/instructions for actual execution tasks). That's one reason why doubling your RAM from 2GB to 4GB and again to 8GB doesnt double your actual performance. Again a faster clocked CPU (3.0Ghz) with 2GB will almost always kick ass over a slower clocked CPU (2.5Ghz) with 4GB (or 8GB for that matter).
And we havent even started talking about CAS latency and Command Data Rates [:wr2:5]

Bottom line - CPU frequency changes have a far larger impact on performance than FSB bandwidth, RAM speed or amount of RAM installed.

Always remember - todays $3000 worth of PC performance can be had for $1500 in 18 months.
My opinion is that you should set a comfortable fixed budget and let the forum members help you build a fully balanced, bang for your bux, kick ass system.
Set the budget, tell people how you intend to use the computer, the types of tasks you will use it for and what's important to you.


June 13, 2008 1:54:56 PM

Thanks WR2, appreciate the explanation, sounds like I need to learn overclocking to get that really amazing performance. Just so you know, I'm looking at 1500-$2200 as an overall spend. I'll be using it so internet 7 windows, some finance comparison software, downloading several thingsa and listening to music all at the same time. I might get a copyof Call of Duty 4 (instead of buying a PS3) and play multiplayer on that online, and from what you've said I'm much more interested in learning overclocking techniques now too. Any suggestions based around this info??
a c 203 à CPUs
June 13, 2008 6:58:53 PM

Just an early first cut based on your budget being for a complete system including peripherals like monitor, keyboard/mouse, speakers, etc.
I used the http://www.scorptec.com.au website for current pricing.
If you have a favorite e-tailer or store you'd prefer to use go ahead and mention that.
And if you have any exisiting kit you'd like to move over to the new system mention that as well - speakers, things of that nature.
For personal preferences do you prefer quiet or understated systems?
Or a bit more flash as in transparent case windows and LED lights?


For the core tower system:
Asus P5K-EPU $160
Xeon 3230 Quad 2.66Ghz $385 (Same as C2Q Q9450 2.66Ghz - $449)
[:wr2:2] (initial overclock goal = 3.2Ghz 400FSB for CPU power equal to $1750 QX9770 3.2Ghz)
Crucial Ballistix 4GB DDR2 800 PC2-6400 CAS4 $160
XFX GF 8800GT 512MB $299
WD WD6400AAKS 640GB 7200 16mb SATA3 $119
Lite-On DH-20A3S DVD Burner SATA $35
Arctic Cooling Freezer 7 Pro CPU Cooler $45
Cooler Master RC-690 case - $99.00
Corsair 550VX PSU - $149.00
$1451

Peripherals
Samsung 2253LW 22" LCD 1680x1050 $329
Keyboard/Mouse = Logitech Cordless MX3200 $129.00
Altec Lansing VS2421 Speakers $79
Vista Home Premium 64bit SP1 $175
$712

June 14, 2008 5:32:43 AM

Hi WR2, thankyou for that suggestion, in terms of understated/ quiet etc, I wouldn't mind something a bit flashy, if looks like more like a spaceship it might help explain to my g'friend where the cash went, in terms of migrating old kit over - I've got nothing worth bringing over, this rig is really a full departure from my existing and annoyingly slow computer, just wondering about the xeon, what's the reason/logic behind that recomendation (don't want sound rude, it's just that I don't understand the xeon's benefits)?
a c 203 à CPUs
June 14, 2008 10:50:22 AM

It's generally thought that Xeon CPUs are higher binned parts than the standard Q CPUs. They're heading to the more demanding server market.
The only benefit is that you can sometimes find them at a lower price than the same Q version. In this case though thats not what happened.

I should have put the $445 Q9450 in the CPU slot in that hardware list. So add $65 more to the bottom line.
I was rushing through the Scorptec website and I grabbed the wrong Xeon. X3230 is 2.66Mzh but its also the Kentsfield 65nm Xeon version of the Q6700 and not the X3350 Xeon Yorkfield 45nm version of the Q9450. The X3230's $385 price is just above what we'd pay for the X3350 $350 USD and I had thought I'd found you a bargin Yorkfield. (I have no idea why you guys are paying $100AUD more for the same part - right now $100AUD = $94USD)
Right now Intel has four socket 775 Quad CPUs on offer @ 2.66Ghz
$349-Q6700 $385-X3230 Kentsfield 65nm 1066FSB
$449-Q9450 $449-X3350 Yorkfield 45nm 1333 FSB
With the Q9450 & X3350 being the same price there is no reason to chose one over the other.

Lets take a hard look at the Q6700 ($349) and Q9450 ($449) at becoming your new CPU.
Both run at 2.66Ghz. Q6700 has 4MBx2 L2 Cache Q9450 had 6MBx2 L2 Cache.
Q6700 FSB runs at 1066Mhz vs Q9450 FSB runs at 1333Mhz. The higher FSB also means higher FSB bandwidth. Time to look at some benchmark that show how the larger L2 Cache and higher FSB bandwidth affect performance. Kentsfield vs Yorkfield I know the benchmarks are using the 3.0Ghz but they also apply to the 2.66Ghz CPUs as well. Also keep in mind that as each gets OC'd that % of performance differences will stay the same.
[:wr2:3] Is the small performance increase of the Q9450 worth spending the extra $100 to you? GST alone doesnt seem to be the difference.
[:wr2:3] Would you consider the Q6600 2.4Ghz ($245) or Q9300 2.5Ghz ($299) keeping in mind that you could also overclock these CPUs to 3.2Ghz the same as the Q9450/Q6700? A slightly more powerful CPU cooler would probably be a good idea also.
I know the idea of overclocking is something you're only now warming up too - but its really not as difficult as you probably imagine. All of these CPUs will OC above 3.2Ghz and that is just an easy starting off point that still gives an amazing bank for buck compared to the 3.2Ghz QX9770 ($1750)

I'll have a look around at options for turning up the flash a bit.
Also I'm not happy with the speaker set I picked. I thought based on Altec Lansing's reputation and the price that they would be a decent set of speakers. It turns out not to be the case. So I'm now suggesting the Logitech X-230 $69.00 or Logitech Z-4 $109 (Z-4s are $70 over here!)

So far I've left off adding an extra 4GB or RAM or a sound card to the build. The reason for that is both can be added in easily (sneaked in) later after the "sticker shock" of the new PC has worn off. Onboard sound is actually quite good these days. And 8GB of RAM doesnt provide a large improvement in peformance in most circumstances. Vista RAM Memory Sizes

edit; added the Q6600/Q9300 option.
Because of the possibility of spending more on the speakers plus adding in a sound card I added an option to use a less expensive CPU.
Q6600 vs Q9300 comparison @ XbitLabs
a c 203 à CPUs
June 14, 2008 8:16:10 PM

Take a look at some of these NXZT cases and see if you find something that suits your style. http://www.nzxt.com/products/
That website also links in reviews for the cases for each model so you can get some ideas of the pros and cons of each case.
Once you find the right case maybe add in an LED Meteor Light for a little extra pop.
Sometimes it just enough to replace the case fans (say the stock or blue LED case fans) with red or green fans for a custom look.
a c 203 à CPUs
June 14, 2008 8:25:28 PM

Here is a link to check the prices on the NXZT cases: http://www.bttech.com.au/nzxt-case-c-105_1320.html

Another online store with a good selection of cases: http://www.pcsuperstore.com.au/

Besides style a couple things to keep in mind.
If it has a door - does it open the right way for your office set up?
Look at the IO port location (USB, headset jacks, etc) and see if that will work the way your PC will be set up.
A floor mounted PC and IO ports on the bottom isnt as handy as top or front ports mounted higher up.
!