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Thunderbird 1.4/266 backwards compatible

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October 7, 2001 5:29:28 AM

Does anyone know if a Thunderbird with a 266FSB will run on a non DDR board? Obviously it will not run at the specified FSB but will, for example, a 1.4GHz run at 1.4Ghz or less since the FSB would be reduced? I want to upgrade but only have the money for the processor right now. the mobo will have to wait until later.

Thanks in advance for any help!
Anonymous
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October 7, 2001 5:34:26 AM

FSB and DDR are two sepparate issues. My A7V133 runs 266MHz FSB Athlons but does not support DDR. Check the motherboard specs, if the chipset is VIA's KT133A or newer you should have no trouble running your CPU.

Cheers!

Bogdan

***Life is Beautiful***
October 7, 2001 7:35:43 AM

The 266 referes to the athlons communication with the northbridge, all thunderbirds can run on 133fsb or 100fsb or even 66fsb(if you wanted to underclock it and the bios allowed you to.)

~Matisaro~
"The Cash Left In My Pocket,The BEST Benchmark"
~Tbird1.3@1.5~
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October 7, 2001 7:55:01 AM

It will work on any Socket A motherboard with the ability to provide a 133MHz bus speed (all the way back to KT133A). The KT133 (prior to the KT133A) will not support the necessary 133MHz bus speed. Oh, and "266" means 133.

Back to you Tom...
October 7, 2001 8:08:08 AM

The 133/266 WILL however run in the 100fsb kt133 boards. The multiplier will be wrong but that can be easily fixxed.

~Matisaro~
"The Cash Left In My Pocket,The BEST Benchmark"
~Tbird1.3@1.5~
a b à CPUs
October 7, 2001 8:22:48 AM

Yes, you can change the multiplier, or you COULD simply buy the 1.4GHz/200MHz version to begin with.

Back to you Tom...
Anonymous
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October 7, 2001 1:01:23 PM

The multiplier is what it is set already. For a 266MHz 1.4GHz Athlon the multiplier is set to 10.5. In a regular KT133 board your 266MHz FSB Athlon (aka 133MHz DDR) will run at 200MHz (100MHz DDR) so the speed will be 10.5 x 100 = 1050MHz.

If the Athlon is multiplier unlocked (most of the higher clocked new AMDs are in fact factory unlocked) you could try to set it manually to 14 so you'll get 14 x 100 = 1400MHz. However there are not too many KT133 based boards that have multipliers that go as high as 14. Most of them stop at 12 so if this kind of compatibility is your concearn, you should check the motherboard's specs and any new BIOS releases for it that may add higher multiplier settings.

Cheers!

Bogdan

***Life is Beautiful***
October 7, 2001 1:43:28 PM

Crash, yeah but it costs more.

The other guy, I know all that lol.

~Matisaro~
"The Cash Left In My Pocket,The BEST Benchmark"
~Tbird1.3@1.5~
October 7, 2001 1:45:05 PM

PS: the reason I posted about your comment crash was.

Quote:
It will work on any Socket A motherboard with the ability to provide a 133MHz bus speed (all the way back to KT133A). The KT133 (prior to the KT133A) will not support the necessary 133MHz bus speed. Oh, and "266" means 133.

It looked as it could easily be mistaken by a newbie to mean that you can NOT run a tbird 133/266 on an older 100fsb kt133 board.

~Matisaro~
"The Cash Left In My Pocket,The BEST Benchmark"
~Tbird1.3@1.5~
October 7, 2001 8:42:50 PM

Thanks for the help guys! I knew I had something mixed up in my head somewhere. That clears things up.

Thanks again!
October 7, 2001 8:55:00 PM

One more thing: My motherborard is a MSI K7T Pro. In order to bring my FSB up to 133 I need to clock my PCI Bus at 43mhz (or something...i havent looked yet). So the real question becomes can the rest of my computer handle the increase? Unfortunately my current Duron 650 wont handle over 112 so I can't find out. Hmmm... well i'll let you guys know what happens. Thanks again for the help.

Oh one more thing - with the latest BOIS will my motherboard recognize the new processor or am I going to run into problems?

Thanks
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October 7, 2001 9:13:24 PM

I'm fairly sure that your motherboard has the necessary 1/4 PCI divider to allow PCI bus clock of 33MHz with an FSB of 133 (aka 266). Yours is a KT133A chipset board correct?

Back to you Tom...
October 7, 2001 10:05:36 PM

I'm not so sure that it's a KT133a chipset. I think its a KT133 chipset. It's only got ATA66 support. I know that there is no way to individually change the PCI bus through the BIOS. If i want to bring my FSB up my PCI Bus must come up too. If there is software support, I dont know about it. Anyway, does anyone know if a K7T Pro will even recognize a TB1.4? I know, I know, upgrade the d*** motherboard, you say. well this one is rock stable and i dont have the money.
Soon.
I hope.

Thanks for the response!
October 8, 2001 2:06:46 AM

It sounds like your board is a 200Mhz DDR(100Mhz real) FSB board only.

You can install a 1400/266 Athlon in it, but I think the most you will be able to boot it at will be 1050Mhz by default.

If your chip is unlkocked, and your mobo allows you to, you (using latest bios) should be able to configure a multiplier of 14x or more. This will allow you to try and set the chip for 14x at 100FSB giving you a 1.4Ghz cpu again.

In reality you can probably overclock your FSB a little, but on that chipset it is a crap-shoot and could be 1-10mhz extra, giving you a theoretical limit of 1155Mhz or so, without adjusting multiplier.

Basically, you can use the cpu, but it will be severely throttled on that board. If your memory is good, you could upgrade to a KT133A board (such as A7V133) however if I were doing it, I would take the hit and drop SDRAM support totally and go fully DDR, either with a Sis735 board (see THG review of such) or with a KT266A (note - get the A revision) board such as the K7T266 Pro2 (the 2 has the KT266A) from MSI...

-* This Space For Rent *-
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October 8, 2001 2:09:32 AM

The kt133 chipset wont be able to hit `115 let alone 133, you cannot get a 133fsb on a kt133 chipset. Sorry.

~Matisaro~
"The Cash Left In My Pocket,The BEST Benchmark"
~Tbird1.3@1.5~
Anonymous
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October 9, 2001 9:33:23 PM

Maybe you guys can take it one step further and indulge me by explaining to me whether or not the Via KT133A chipset supports Thunderbird processors above 1.3 GHz. Judging from your posts, yes. Specifically, Asus' website says the Asus A7V133 with the KT133A chipset supports 1.3Ghz+ processors, so does that mean that it'll support 1.4? And on? What's the limit?

Thanks,
tslugmo
October 9, 2001 11:00:57 PM

Yes, it will. You *might* need a BIOS update, but it'll work. I've run my 1.2/266 at 1.4/266, so you should have no problems doing the same.

<font color=green>I post so you don't have to!
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Anonymous
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October 10, 2001 11:59:27 PM

Thanks for your quick reply, Fatburger. Guess I should have clarified, I don't mean could I run a 1.2 GHz at 1.4 Ghz on the Asus A7V133, I mean how limited will I be with this motherboard for the future? I'm trying to decide between the Asus A7v133 with the Via KT133a chipset and perhaps a mobo w/ the Via KT266A chipset. I'm wondering if I will still be able to upgrade my processor in a year (who can predict where technology will go, I understand) or will I have to buy a new mobo, too? I mean, 18 months from now, can I put a Palamino 1800 + Athlon in the Asus A7v133? Or do I need the KT266 chipset?

Thanks,
e
October 11, 2001 4:20:09 AM

if you have the moolah, definately go for the KT266A... grand performance increase with ddr.

also other great chipsets for ddr are:
SIS 735
and the upcomming SIS 645 & nvidia Nforce

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