What is Vtt voltage?

C

CBR900

The Salmon of Doubt
#1
What is Vtt voltage? and why is mine only at 1.25v instead of 1.5v?
What affect does this have?

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CelT [email protected]
ST6 mobo
Maxtor ATA133 7200rpm 20gig
256Mb PC133 CAS2
R8500LE (310/325)
W98SE / Directx8.1
3DMARK2001 8137
 
U

uart

New Member
#2
Sounds like it might be a "termination" voltage". Is this listed as a seperate voltage to the I/O and core voltages? BTW, what's your core voltage reported as?

If you post what other voltages are reported then we might be able to figure it out by process of elimination.
 
C

CBR900

The Salmon of Doubt
#3
vcore 1.48
vtt 1.25
vio3.34
+5 is 5.06
+12 is 12.23
-12 is -12.11
-5 is -5.1
5vsb is 5.09
vbat 3.01


thanks


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CelT [email protected]
ST6 mobo
Maxtor ATA133 7200rpm 20gig
256Mb PC133 CAS2
R8500LE (310/325)
W98SE / Directx8.1
3DMARK2001 8137
 
OneEng

OneEng

Speculator Extraordinaire
#4
Vcore is ... well core voltage, or the voltage supplied to the CPU.

VIO is the input output voltage used primarily for the PCI and AGP cards, but is also used for the 3.3V logic chips on the main board. Once upon a time VIO was simply VCC or in english +5Vdc which most chips made worked on. This was the TTL (Transistor to Transistor Logic) gate standard for quite a long time. Since die shrinks have occured, logic gates require less voltage and less curent than the old days, and the current "standard" is 3.3V. Look for this to change to 2.5V in the near future.

+12, -12, +5 and -5V are all the old standards that have been included in powersupplies since the creation of silicon transistors. These voltages are created by your powersupply and routed to your motherboard. On the motherboard, switching regulator chips that are controlled automatically from the bios programming of the board regulate all other supply voltages.

And finally (to answer your question) VTT is (as UART has suggested) termination voltage. It is used to power the RAM on your computer. This is kept seperate from VIO and VCORE on better motherboards in order to allow different voltages for all 3 subsystems. As memory undergoes more die shrinks, this voltage will get lower also.

Hope this helps.

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With greater knowledge comes greater understanding!
 
D

DuronClocker

.
#5
I thought it was the cache voltage for the chip. ol' man would really be the one to answer this one..

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MSI K7T Turbo-R w/ 2.35v/4.05v mods
AthlonXP 1600+ @ 1800+ 1.55v 41'C
256MB Corsair PC150
Radeon 64DDR SE @ 315/240 w/ ramsinks + default coresink...one volt mod done!
 
D

DuronClocker

.
#6
Oh, and to answer the second part of your question, this voltage should be 1.25v. The Cel-T, like I believe all new .13um processors, differing votlage between the VTT and VCC. VCC is the core voltage. The reason behind this is something like the cache is designed differently and requires less voltgae. I do know that this is a part of the pin trick to get it to work on a BX board...you have to be able to drop the VTT voltage so the chip doesn't fry itself. Kind of like the old Pentium-class split-voltage chips that required split voltages (like the K6-2 and some Cyrix's).

------------------
MSI K7T Turbo-R w/ 2.35v/4.05v mods
AthlonXP 1600+ @ 1800+ 1.55v 41'C
256MB Corsair PC150
Radeon 64DDR SE @ 315/240 w/ ramsinks + default coresink...one volt mod done!
 
C

CBR900

The Salmon of Doubt
#7
S*it I love this board, so many intelligent people....I just wish some of them would answer my questions

Really thanks guys, I have had a look around too...and I also now think the vtt should be 1.25
The reason I was worried it was low, was because my bios lists it as 1.5v then reports it as 1.25v

------------------
CelT [email protected]
ST6 mobo
Maxtor ATA133 7200rpm 20gig
256Mb PC133 CAS2
R8500LE (310/325)
W98SE / Directx8.1
3DMARK2001 8137
 
O

ol' man

workin fingas to the bone
#8
All the vtt pins on the tualtin are on the side of the cache. I would guess it supplys the cache bus with its juice? Yes the tualatin is supposed run with a 1.25v vtt while the cumine ran with 1.5v. i though the ram ran on a I/O voltage of 3.3v or whatever it is set at on your mobo.

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1.2Ghz cel-t @ 1.6GHz/1.65v

Off Topic Central
 
USSVoyager

USSVoyager

Excuse the name
#9
Yeah, isn't SDRAM at 3.3V and DDR SDRAM at 2.5V?

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Gin - The driver's choice
 
D

DuronClocker

.
#10
Yep

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MSI K7T Turbo-R w/ 2.35v/4.05v mods
AthlonXP 1600+ @ 1800+ 1.55v 41'C
256MB Corsair PC150
Radeon 64DDR SE @ 315/245 w/ ramsinks + default coresink + vmem mod...workin on core mod
 

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