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What's wrong with FSB architecture? (Core 2 Duo / Quad)

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First of all I'd like to let you all know that I know FSB has been around for ages.

But I am confused. On a series of forums, I have seen people asking "will my Q9000/Q8000 be able to handle SLI /CF?"

While many answer "yes", some will say that the FSB architecture might become a bottleneck.

Does this really happen? I know FSB is slower than QPI or DMI (if you compare an i5 760 to a Q9550, there isn't much difference), but does it create serious bottlenecks?

Wouldn't there have to be like 4 GPUs and 12 cores to saturate an FSB?

I remember the skulltrail had 2 LGA 771 sockets for dual QX9775 action, and it scaled amazingly. And that was achieve with the FSB architecure.


Are FSB bottlenecks overrated?
 
I think it depends.

With todays CPU's the IMC in on the CPU itself instead of the northbridge, and while that doesn't mean that one is necessarily ''better'' then the other, but it help's improve performance and latency a bunch, giving you faster CPU to RAM access times. It has been said that a slow FSB does bottleneck a fast CPU, if the CPU itself is blazing fast, it's still going to take up more clock cycles to retrieve data and instructions if the FSB is slow hence slowing down the entire system.

Whether or not a CPU is a bottleneck for a GPU depends all on which CPU and GPU we're talking about. But considering the GPU still has to go though the northbridge, having a slow FSB could potentially be a bottleneck between both CPU and GPU.

But im no expert really..
 
Well, the fastest FSB that they used of 400MHz has a FSB that theoretically provides 12.8GB/s. Dual channel DDR3@1600MHz can saturate that just by itself, and triple channel memory goes way beyond that.

That alone is reason to move away from FSB.
 
But those are all theoretical situations.

In real life, it's much harder to saturate and create a bottleneck with an FSB, especially if overclocked. Am I right?

Let's say for gaming; is it a necessity to move away from the FSB? Doesn't seem like it. But I'd like your opinion on that :)
 
But those are all theoretical situations.

In real life, it's much harder to saturate and create a bottleneck with an FSB, especially if overclocked. Am I right?

Let's say for gaming; is it a necessity to move away from the FSB? Doesn't seem like it. But I'd like your opinion on that :)

It is harder to saturate it with what was produced using FSB. However, it would be easy to saturate if the move to triple channel memory was done with the FSB architecture.

Plus with FSB, everything had to move over the FSB. So on top of the memory there was hard drive activity, and video card activity. So FSB was holding back developement of faster technologies.
 
It is harder to saturate it with what was produced using FSB. However, it would be easy to saturate if the move to triple channel memory was done with the FSB architecture.

Makes sense., but LGA 775 only supports dual channel DDR2/DDR3.

But for gaming, systems relying on the FSB, still have a couple of years ahead of them before starting to bottleneck even single GPUs, right?

Maybe even more that.
 
Makes sense., but LGA 775 only supports dual channel DDR2/DDR3.

But for gaming, systems relying on the FSB, still have a couple of years ahead of them before starting to bottleneck even single GPUs, right?

Maybe even more that.

Right, thats my point. FSB only supports dual channel because anything beyond that was impractical due to the limitations of FSB.

But really, for normal users and even single graphics card gaming, FSB is still good enough. In fact triple channel RAM doesn't really make a huge amount of difference in most things, including gaming, right now. That is why clock for clock an i7 800 chip is pretty much just as fast as an i7 900 chip. However, there are a few things that do show a pretty reasonable difference with triple channel RAM(high end graphic editting and rendering and video encoding).
 
i thought it was just a technical term - once the IMC was moved into the CPU it stopped being an FSB, since FSB was the link between CPU and NB (and it was no longer an NB without the memory controller)
 
i thought it was just a technical term - once the IMC was moved into the CPU it stopped being an FSB, since FSB was the link between CPU and NB (and it was no longer an NB without the memory controller)

So, in your opinion, the FSB does not constitute any serious bottleneck in "normal" applications? Like gaming.

For example: Quad Core CPU + High-end GPU.
 
So, in your opinion, the FSB does not constitute any serious bottleneck in "normal" applications? Like gaming.

For example: Quad Core CPU + High-end GPU.

no. just the design of the CPU in general.

EG, you get a pentium 4 at 5GHz, and its still gunna suck.


in a few years time core 2 duo will be just as old and slow, especially as you add more and more powerful GPUs.
 
AM3 works much in the way that s775 did. The FSB (for Intel) and North Bridge (for AMD) can definitely, without a doubt cause a bottleneck, especially with CrossFire/Sli if the bandwith isn't high enough.
 
I would like to keep this system for another couple of years, and staying Single GPU.

Is it realistic to keep a Core 2 Quad relevant 2 years from now? I mean, single GPUs won't need that much bandwidth, to the point of clogging the FSB.
 
I would like to keep this system for another couple of years, and staying Single GPU.

Is it realistic to keep a Core 2 Quad relevant 2 years from now? I mean, single GPUs won't need that much bandwidth, to the point of clogging the FSB.

Nah, you should be good. If anything, down the road and you buy the next great GPU and aren't satisfied with your experience, upgrade then.
 
we almost have identical systems -Im going to have mine for a good nother 2-3years, I'l just throw in a USB 3.0 PCI expansion card n maybe slap a Sata 3.0 controller card in as well if i really need the speed..

but one thing im really getting sick of is my Antec 902 - the case is a dust magnet so i might buy a new case n just migrate everything over
 
we almost have identical systems -Im going to have mine for a good nother 2-3years, I'l just throw in a USB 3.0 PCI expansion card n maybe slap a Sata 3.0 controller card in as well if i really need the speed..

but one thing im really getting sick of is my Antec 902 - the case is a dust magnet so i might buy a new case n just migrate everything over

Yeah, we still have pretty powerful rigs.

These Q9550 are monsters :D
 
really the only thing to upgrade with your system is either a new GPU, HDD/SSD or soundcard, I already have most of those so all i really can do with my system now is get an SSD, new GPU. or put in sata 3.0 controller cards n hdd's.

If recent games are anything to go by - all you will really need is a GPU upgrade since console ports dont push the limitation of GPUs but your 4890 might be struggling a little with some of the current games.
 
really the only thing to upgrade with your system is either a new GPU, HDD/SSD or soundcard, I already have most of those so all i really can do with my system now is get an SSD, new GPU. or put in sata 3.0 controller cards n hdd's.

If recent games are anything to go by - all you will really need is a GPU upgrade since console ports dont push the limitation of GPUs but your 4890 might be struggling a little with some of the current games.

Not @ 1280x1024 :D

One of my friends has an HD4870 and plays @ 16x10 an he gets great framerates still.

HD 4890 is still a powerful GPU, I would say.
 
well, all i know is my overclocked 5850 struggles a little with my 23" in some games so getting it crossfired or upgraded is a must - BUT i think i will get the case first
 
I would instead wait for the new HD 6900 series.

Save the hassle of multi-GPU setups, and get a single fast GPU.

You can still sell that HD 5850 for a decent price to cover for the new GPU.
 
@ FreedomEclipse and MaxAwesome: At medium settings, my HD 4850 can even somewhat handle Metro 2033 (except for the actionful parts of de D-6 level, which lag a little at those settings) at my screen resolution of 1280x1024. I will never have a Full HD or multimonitor setup, not even if I can afford it, as long as you need more then an upper mainstream pc to do some decent gaming with such screens. I mean, Metro is the exception when it comes to having just enough power for it. Other games run nicely on it.
 
I think when I need a faster card I will need to get a faster cpu also.
The Q9550 and the HD5850 are almost perfect for each other.
 
A Q9550@4GHz is a serious performer and especially in gaming and will be for some time. Even in Starcraft 2 ( which is quiet CPU heavy ) it will hold its own and often deliver really good temps under a good cooler.
 
I would instead wait for the new HD 6900 series.

Save the hassle of multi-GPU setups, and get a single fast GPU.

You can still sell that HD 5850 for a decent price to cover for the new GPU.

could do - but imo theres nothing thats gonna make full use out of the 6900 series cards. pc games are console port after console port (at least it is for shooters which is what i mainly play) so spending hundreds on a 1 off powerful card seems like a bit of a waste at the moment when I can pick up a 2nd hand 5850 for around £100ish and 2 of them would just pwn anything i throw at it and pretty much anything thats gonna come out in the next year or 2. unless the industry has a change of heart and goes back to their roots and start making games for the PC and not just a game that gets ported to save money. then maybe it would be worth upgrading.

black ops was only DX9 ffs - I 'downloaded' the game to try it before i bought it and after playing it for about an hr. ive decided to save my £35 and spend it on some new valves for my guitar amp.

their not pushing the boundaries anymore so I dont feel any real need to go over the top and upgrade to something which i will never see get used to its full potential. and for that reason, and because 2 5850's scale incredibly well with each other ive decided on a 2nd 5850
 
I would instead wait for the new HD 6900 series.

Save the hassle of multi-GPU setups, and get a single fast GPU.

You can still sell that HD 5850 for a decent price to cover for the new GPU.

Amen to that! I prefer a single powerful GPU any day to avoid the glitches and inherent scaling limitations of sli/crossfire.

@ FreedomEclipse and MaxAwesome: At medium settings, my HD 4850 can even somewhat handle Metro 2033 (except for the actionful parts of de D-6 level, which lag a little at those settings) at my screen resolution of 1280x1024. I will never have a Full HD or multimonitor setup, not even if I can afford it, as long as you need more then an upper mainstream pc to do some decent gaming with such screens. I mean, Metro is the exception when it comes to having just enough power for it. Other games run nicely on it.

Re the 1280x1024 resolution, I think you're unnecessarily limiting yourself there. I'm still using a GTX 285, which is only considered mid range by today's standards. However, it's still very powerful and runs my games at well over 60fps on my 1920x1200 monitor. You have a 4850, which is significantly less powerful and won't handle high res nearly as well.

If you upgrade to something like a GTX 460 or similar (which has about the same rendering power as my 285) you won't have to spend much money and you can use those beautiful high resolutions with smooth gameplay.
 
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Nearly 200 for a decent card, plus roughly 200 euros for a monitor (lower means crap, most likely) and whoppa! There goes my money! How could I possibly afford that as a student? And I don't like throwing away stuff that still serves me. And I have sworn to myself that the power draw for a graphics card should be equal or less compared to the one of my 4850. Else I will use more power for roughly the same framerates. Pointless.
 
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