Dual Core AMD on a 1600 MHz FSB mobo ? 2

[transtec]

Hi ppl,

I own an AMD Athlon 64 based system and it's been 2 months since Ive put it together by myself. It's my second PC and my first AMD experience !

The motherboard is Gigabyte's GA-K8NF-9 which uses the nForce4 4x chipset and the CPU is an AMD64 3.0 GHz ( 1.8 GHz Winchester clock ).

This whole setup is damn gud ( boots completely in 30 secs WinXP 64 bits ) and I wudn't be complaining at all. But its jus my nag at upgrading that I think i wud be planning in on goin dual core in no time soon, jus for the fun of it .

But there seems to be a problem to it. The mobo only operates on 1600 FSB and the dual cores all go on a 2000 FSB. My question is : Wud I be able to upgrade into an AMD dual core processor using this same motherboard ? If i do wud there be a performance hindrance to it bcos of the slow FSB ?

BUT... the mobo doc, the box in which it came and even Gigabyte site says that the mobo does support dual core CPU's but im not much happy bcos of the slow FSB that thesse fast CPU's wud be demanding.

thanx ...

 

[cdogg]

I think you are referring to theoretical speed when you use the number 1600 (but that's for the older socket 754). However, the Winchester Athlon 64's actually run on a 200MHz FSB x 5 = 1GHz (which is 2GHz theoretical).

Your mobo specs are here:

http://www.giga-byte.com/MotherBoard/Products/Products_Spec_GA-K8NF-9.htm

As you can see, you've got a Socket 939 chipset which supports the Athlon X2 (dual-CPU) at the full FSB speed. I think you need to take another look at how you came up with the numbers 1600 and 2000...

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[paparazi]

I agree, cdogg is spot on, you will have no slow downs with this board and an X2.
You will need F7 bios or newer to support the dual core.
Gigabytes are real easy to update, they have the flash utility already built into the bios so all you need is the extracted flash file writing to floppy, enter Qflash in the bios, follow the instructions.
Reset after power down.
Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[transtec]

Ohh sorry its bin two months since i was quite literate on these terms while searching the net, reading reviews and news on AMD. What I was meaning to say was that the Board actually supports a Hyper Threading speed of 1600 MHz as opposed to other nForce4 boards supporting the full 2000 MHz Hyper Transport link. This spec is also mentioned in the "specs" section of the link you gave me, cdogg. The mobo is already on F7 BIOS - factory installed, paparazi.

And goin thru this page [

http://www.gamepc.com/labs/view_content.asp?id=gbnf44x&page=2

] I found that the board actually is the only one in the market built using an nForce4 pre-release type of chipset ( the A2 revision ). This makes it operate the hyper transport at an unusual speed of 4 x 200 MHz = 800 MHz which effectively turns out to be 1600 MHz.

One thing I need to mention is that my particular motherboard doesnt have a fan for the Southbridge ( or the Northbridge , whatever you call the nForce4 chip as ). Instead all i see is a huge gold colored heatsink and it currently heats up a lot under normal configuration. Thus overclocking the Hyper Transoprt on this mobo would be fatal, I believe.

So my question still remains as to where in would i lose performance if I install a Dual Core CPU on this MoBo ?

 

[cdogg]

First of all, Athlon 64 CPU's have the memory controller integrated on the CPU itself, and is no longer located in the Northbridge. Overclocking, anyway, should be an afterthought at this point.

But you're definitely right about your board. It appears to be a rare Socket 939 that has the 800MHz limitation.

The good news is that according to the article you posted:

We were able to move our HT Frequency up to 5x / 1000 MHz with this BIOS setting, and surprisingly, the board was completely stable throughout our benchmarking.

If you want to be completely safe about it though, I suggest you sell this board for whatever you can get and buy a different model with a newer version of the nForce4.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[transtec]

I have no hopes of selling the mobo. All I want is to replace the CPU so that I cud install a 3800+ dual core on it.
But if a dual core CPU is gonna run slow on this mobo cos the Hyper Transport link is only at 1600 MHz and not the full 2 GHz which the new CPU's cud handle, I think i mite not be getting what i pay for if i install a dual core....

All i wanna know is what is the impact of the Hyper Transport bus speed and how would a performance boost of 400 MHz to a 1600 MHz have an effect on the speed ? Will I achieve the full speed of a dual core on this mobo ?

Keep in mind Im not a serious gamer. I enjoy doin a load of multitaskin as well as encoding video. Although the Athlon64(Winchester) 3 GHz I hav currently is more than suffiecient for my needs, i mite do an upgrade if the need arises maybe 6 months down the line

 

[paparazi]

With what you are saying, in theory I guess you have a slight bottle neck, in practice however I doubt this amounts to much performance loss at all, nothing you would notice in use unless you benchmarked and then it would be extremely minimal.

Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[cdogg]

transtec,
Because you do a lot of multitasking, a dual core is the right solution for you. I also understand your concern about the 800MHz Hypertransport clock speed (1600MHz theoretical).

The article you posted mentions that the 800MHz limitation does not show any signs of having much of a disadvantage when using a single core. That analysis is also in agreement from what I've read at other sites. The reason is because the Hypertransport bus is still running on a whole number multiple of 200MHz (in this case 4). The CPU's internal multiplier is also a whole number integer that is multiplied by 200MHz. Because there isn't an odd ratio between the CPU clock speed and Hypertransport, the 800MHz limitation isn't much of an issue. The dual core CPU will still run at full clock speed, and you will see an improvement over what you have now.

The only disadvantage really, would be shown in a benchmark between your board and one that supports the 1GHz Hypertransport bus. I would caution judgement on this, however. I'm sure that a couple benchmarks would show a slight bottleneck as paparazi mentioned, but I would almost challenge any assumption that you could ever notice the difference. Such differences are usually only shown in "synthetic" benchmarks which measure potential, and not necessarily real-world applications.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[transtec]

Thanx a lot paparazzi and cdogg ! You both owe credit for solving my mystery. Well I guess now that it is done, all i shud do now is luk for a gud dual core porcessor and get it instaled on ma mobo.... Well anyways ive decided Im not gonna throw away my mobo jus for the Hyper Transport issue. As long as there are two cores there to server for me, i wudnt give much concern whther my mobo wud be doing better than anther nForce4 mobo.

thanx a lot guys!