I wanted to take up a debate over the available Core 2 Duos, both 2 core and 4 core. More specifically the Extreme Editions (X6800 and QX6700).

I have heard many opinions on which one is better and why.

Quite frankly many of the "whys" have been somewhat miss informed. (yeah I said it )

I have heard the dual core is better because its base speed is better and no software is available for dual core let alone quad core.

I have heard that the quad is better because it has more cores (more is better right?).

I have heard people turn others away from dual core because of encoding/decoding tasks.

I have heard people turn others away from quad core because of heat issues.

I have seen this argument segmented into Gaming and Non-Gaming applications to prove someones point as well. Are they really different? Do they have to be? Are they going to be?

So the question is:

Which is BETTER and WHY?

Please try to keep this as a Tech response only. I would like to address Software/Hardware and even OS as possible reasons for OR against.

I would also like to add that for this thread the WHY is very important.

I have added the Poll question just to make a short sweet data point (more for amusement then anything else).

It obviously depends heavily on your usage, but I would say the QX6700 is the better buy considering they are virtually the same price.

In single/dual threaded applications, the QX6700 would be at most 10% slower than the X6800, purely due to the lower clockspeed on the QX6700. However, in heavily threaded applications (video encoding and 3D rendering for example) the QX6700 can be up to 80% faster due to the extra cores.

I would have to agree, yes the quad core is slower but just based on price I would have to go with the 4 core chip. Granted the most important reason for 4 cores is to be able to do multiple things at once and no at this time very few single programs will use all 4 cores but as they get more popular, which they will when prices come down for regular people more programs will be written to take advantage of the multi core chips. And as for the slight speed difference between the extreme editions of both chips that what overclocking is for.

Some things may be slower initially with the QX6700 but as more programs and games take full advantage of multi-cores it will be much faster. It also has more computing power and will extend your time before your next upgrade. I would without a doubt choose the quad core, you will see more advancements on the multi-core side of technology than you will on speed side(mhz). The times were the 6800 would be faster would hardly even be noticeable however the instances were the QX would be faster are usually fairly significant. The difference in mhz is only about 266 anyway thats not enough to make up for 2 more cores.

Its worth adding the fact the QX has 8mb of L2 cache which more cache at the same speed improve performance by itself.
I think the only person who voted for the 6800 may have been drinking.

BY the time any popular software comes out got multi CPU, either choice as you have today wil be wel redundant anyway.

That is my first reply and straight into the deep. 8) Obviously quad core is better and will last much more. That's due the fact of almost all, cpu heavy, applications starting to be multithreaded. From gaming, (see valves 3d engine for HL2 episode 2,3 and also Crisis), to 3d creation and Vista OS. Btw you can overclock a cpu but you can't add cores!

If the samll speed difference on 1/2 thread apps matters, you can easily overclock a QX6700 to 2.93 ghz, these things usually go deep into the 3.xx ghz range, so that 266 mhz clock is not an issue.

On apps that are deeply threaded (multimedia, some games) 4 cores kill 2.

The poster who said you can always over clock, but can't ever add cores was dead on

By the quad - not even close.

To be fair, you can overclock the X6800 as well, and it will generally overclock further than the QX6700 simply because it runs cooler and has a lower chance of a 'dud' core amongst the ranks. Remember an overclock is always limited by the 'weakest' core on the die.

For example, if the QX6700 has 3 cores that will reach 4GHz but 1 that only does 3.5GHz, then 3.5GHz will be the OC limit. Of course this example is a bit extreme as you'll rarely find more than a 100 - 200MHz variance between cores from the same die, but you get the idea...

theres alot of media software that support mutli cores

Thanks for the replys so far.

I am very happy so far as to see many people have the right answer to the question.

Anyone out there think the X6800 is the better deal?

I was hoping to debate things like temps, scalability, FSB, OS handling of multiple cores, context switching, blocking/interrupts, IO, Memory usage/issues, cache setup/issues.

Anyone want to take a stab at any of those?

Anyone want to fire the first shot?

So far no debate. Just accolades for the Quad.

If nobody wants to start I will give it a shot tomorrow.

Again thanks for the replies so far.

There is no debate if, 1) u are going to vista which supports multi-cpu's, 2)if you planning on "kick butt" system for the future. Quad core is the only way to go. Research it, no debate needed. Nice thread, though!

If you plan on upgrading to qc later, using a low end c2d for now- make sure u get a down firing 12cm cpu cooler such as thermal right with intel type press pin attachment - to make your change over easy with out mobo tear down.
you need a killer cooler for 135 watt beast oc its hot!

I have been building oc systems for 4 yrs now - I shipped my first xtreme 4.1 in 2003 max @4.25ghz and built air cooled xtreme2 4.4ghz 965's (4.6ghx max) - u need the thermal right cooler for the qx or q series. This was before thg articles (4.1ghz air cooled systems) or dell even let peeps oc.


My x6800 is been sitting in box for 3 months for my $4k gaming rig - since their is no drivers for vista/ 8800 and the r600 is delayed. Know my x6800 is going in a shuttle and qx or q series is going in my gaming rig. I build systems and take parts as profit/pay continuously.

For me and my vista machine its either qx6700 this month or wait for q6600 as their is no drivers yet for vista DX10.


edit /add-- i see almost 25% peeps think the x6800 is faster - thats the same reason that amd is over rated. Let me explain first, until just recently nobody did multitaksing tests other then synthetic which u can design software/drivers around. amd is faster until u run antivirus/ music/ game /10 browsers open then u really see multitasking.

I bet the 25% that voted for the x6800 are really well informed but they may not realize that even today only few multitasking tests might mean 2 tests running.

All i do is build and test - try running 5-6 programs u see that q-core is much faster as is intel vs amd.


sorry for the poor grammer skills while i multitask!

Hey Mike welcome to THG,

I want to challenge you on your statement:

Why would a multithreaded application work better on a quad rather than the dual?

I ask because if there are only two main threads instantiated would it STILL be better to own a quad core?

I am doing this to get some folks here thinking at the full system level versus just the application or hardware or OS level.

I personally would buy a Core 2 Quad. When comparing overall system performance, MP3 encoding (i like composing music etc on my pc), film making, photoshop, even boot times, you can see that the quad is a much faster overall CPU than the Duo.

However, if all i did was game and i was buying an OEM pc i would buy a Core 2 Duo thanks to the higher CPU speed.

Just my £0.02 ($0.04 )

More cores = longer staying power. When programs come out that can utilize 4 cores that many people use (besides video / audio rendering), you'll see the C2D line fade out or become the premire chip set for older single threaded video games and older OSs.

If you do multitasking, quad seems to be the way to go. There's about a 40 dollar price difference on NEWEGG right now between the qx6700 and the x6800. If you really feel like you need those few extra mhz, just OC the qx6700 a little and put it on par.

One thing I am a little hesitent on is purchasing a qx6700. With the advent of new intel sockets coming up, I'd rather save my money and get a "true" quadcore and have a socket that isn't at the end of its life, plus DDR3.

If I had to pick now, I'd get the quad core, hands down.

Ok here we go,

Now many folks are thinking along the lines such as the statement (not picking on ya ):

I would dare to say that EVERYONE multi tasks. Many just do not know it. If you look at your system upon startup I would again dare to say that there are MULTIPLE processes in your process list and multiple services running as well.

You are in effect already multitasking. If by chance you have an OS that recognizes BOTH or ALL cores then the OS should start to move those processes around "or NOT" to allow for more efficient system processing.

The above thought is at the "Application level".

Back in 1996 DEC (Digital Equipment Corp) released one of the THEN hottest machines available within the SMP market the DEC Alpha 8400 series. This machine was able to handle multiple gigs of ram and also up to 8 processors. The OS was able to handle all these resources as well. The problem for DEC came when everyone found out the ALL IO routed through CPU0 therefore creating a bottleneck for IO intensive applications such as large database fetches.

When you did a top and looked at the CPUs you would see a pretty good distribution of the applications/use of resources (with the above exception).

My point here is "The restriction of IO to throttle through CPU0 only was an OS issue that was later remedied. The hardware was more than capable but was not ALLOWED.

Not sure if Process Monitor HERE will tell you which core the proc resides on. Maybe I will try it this evening when I get home. Would be nice to see the full process breakdown by core.

The X6800 will be 10% faster in most apps, but you won't notice it anyways. The QX6700 will be 50%+ better in a few select apps and you will notice it.
If I could, I'd go with the quad.

Ok now I am picking on ya j/k

Now this statement brings up the glued together issue (sorry for using a Horde term).

Since this Quad by some standards is NOT a "TRUE" Quad what are we left with?

A Hybrid of two dual cores? Does the fact that the 8mb of shared cache cause thrashing between the now FOUR cores?

Does the way the two dual cores communicate hamper their performance and therefore their success?

What does a dual dual core do to scalability over a TRUE Quad?

Are we now talking about a 1.5:1 scalability vs what could have been a 1.8:1? Is it lower even still?

Does the added OS overhead to manage the third and fourth cores and resources cause a slow down?

Any takers?

K Rock,

Is it fair to totally clean a system (shutdown all unused apps, shutdown all unused services...) to run a benchmark against multicore processors?

I think it is not a true representation of their potential use let alone what most users would have going most of the time.

I am an old dog so when going into games I tend to shut down all not needed apps just to squeeze out that last little bit of performance (old habits that HAD to be done back in the day "uphill both ways" ).

But to be fair I really do not HAVE to do this much anymore because of the resource rich machines now available.

Is it a little MORE fair to leave background processes running that the normal user probably will too? I think so.

Where are the now 7 X6800 folks?

Like to chime in with a why?