CPUs > VIA > Cyrix III/C3

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History
Models
Models (list)
From collector's point of view

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Models

With the many variations of cores, and with a fairly large frequency range available, from 433MHz to 1.4GHz, there were many models of VIA Cyrix III or C3. Not as many as Intel's Celeron models, however, due to a much smaller variety of packages.

The Cyrix III

The first C3 were named Cyrix III, as seen in the previous chapter. We could only find them in the CPGA-370 package, with a golden heatspreader, a heritage of the latest Cyrix and some IDT Winchip 2.
This detonated a bit with the target of the low-cost market, at a time or most competitors had long since abandoned gold, and even ceramic, for plastic packages. Morevoer, what was really the use of an heatspreader for a so low power CPU ?
The first models on the market started at 500MHz with a 133MHz bus, but were soon joined by an entry-level model at 466MHz. Models with a 100MHz bus were also released, to be compatible with motherboards that did not have a 133MHz bus, with a 440BX chipset for example.
Which in the end gave a full line of 11 processors ranging from 466 to 800MHz, with all possible combinations of FSB and multiplier, with the classic duplicates at 600 and 800MHz in FSB100 & 133.

The C3 Samuel 2

From the Samuel 2 core, the Cyrix IIIs are over, place at C3, even if, as we will see in the next chapter, some Cyrix IIIs were also be renamed as C3 and if some Samuel 2 had, not for long, the Cyrix III marking.
In order to distinguish them from Samuel of the same frequency, VIA did like Intel with its Mendocino Celerons, they added an A after the frequency marking : without A, no L2 cache, with A => L2 cache (64Ko here).
Other than that, they were physically in every way similar to their predecessors :

The first models started at 600MHz, the last at 800MHz, so 8 models in total , again with all the combinations of FSB and coefficients possible between the two. All duplicates with the Cyrix III Samuel, which they eclipsed relatively quickly, the time to empty stocks ...
The C3 Samuel 2 were also the first to have a "Mobile" version and a new format that VIA then called EBGA, this that we will see in a dedicated chapter at the end of this page.

The C3 Ezra

The C3 with Ezra core range from 733 to 933MHz and are physically identical to the Samuel 2 of the same frequency, except that on the back cover, they have on their marking a mention like A350xxx while the Samuel 2 have one like AG40xxx.
We can also distinguish them by their voltage: 1.6-1.65V for Samuel 2, 1.35V for Ezra..

On the other hand, Ezra-Ts are much more difficult to distinguish from Ezra of the same frequency. In theory, according to the literature commonly found on the net, only models at 800 & 866MHz should have existed with both the Ezra and Ezra-T core.
But in practice, there were Ezra up to 933MHz, we can find some in the overclocking bases... No Ezra-T below 800MHz though.
Visually, it is impossible to distinguish an Ezra and an Ezra-T : it is necessary to test the processor and to go through the CPUID instructions , using a CPU-Z type program for example.
The Ezra have for the "Model" field the value 7 (and the stepping 8 and beyond, which distinguishes them from the Samuel 2, which have the same value for Model, but a stepping between 0 & 7), while the Ezra-T have the Model field equal to 8.
The Ezra C5M have steppings between 0 & 7 while the C5N have a stepping 8 and above.

The C3 Nehemiah

Theoretically available from a frequency of 1GHz, which was supposed to distinguish them from Ezra, we cand find in practice from 866MHz.
There are several ways to distinguish them from Ezra. The simplest : they are the only C3s to have capacitances on the surface, distributed on each side of the Heatspreader. Usually 4 on right side and 3 on other sides for a total of 13 (out of 25 pads on ceramic).
The marking and voltage check methods also work : the Nehemiah have an AG60xxx type marking on the back (examples: AG60AB0, AG60AB1Q, AG60BK0, AG60FH0 ...), and a voltage most of the time equal to 1.45V, or even 1.4V, and 1.25V for the only Low Power (LP) version known in CPGA format.
But never 1.35V like Ezra or Ezra-T.
Beyond 1.0GHz, there are only Nehemiahs, whose frequencies peak at 1.4GHz .
In addition, like the C5C, C5M or C5N, it is visually impossible to distinguish the C5XL and the C5P, which is a big pity because only the latter have AES hardware encryption with the VIA Padlock ...
Even worse, only C5XL stepping 3 and above have the Padlock Random Number Generator (RNG). In other words, below stepping 3, no Nehemiah has the VIA Padlock function supposedly sold with them...

EBGA models

In order to reduce their cost and size for mobile applications, VIA created a new proprietary BGA format, which it named EBGA. It was in practice a BGA format just like what Cyrix had done with the MediaGX, same size, same packaging technology, but with 368 balls instead of 352.
The first models to be released under this format were the Samuel 2, but there were very few. If we except the "special" versions, described in the next chapter, only one model at 733MHz and one at 800MHz is known, the latter being the only one to appear officially in the VIA datasheets.
The Ezra or Ezra-T did not a priori have the chance to get a mobile version, even if a doubt remains on a 933A model at 1.35V, and with a AG60xxx type marking. 1.35V is indeed the voltage of the Ezra, while AG60xxx is supposed to denote a Nehemiah core. However, we know that the first Ezra-Ts had AG60 marking, so it is quite likely that it could be an Ezra-T actually.
In any case, the VIA datasheets do not help us on this model, because no 933A version is referenced, whether it is Ezra (-T) or Nehemiah core ...

Then came the C3 core Nehemiah, with standard versions from 1 to 1.4GHz and Low Power, 800MHz and 1GHz, at 1.25V.

Later, the C3 EBGAs have been sold as "Mobile" processors, first under the name Antaur (only 1 model), then under that of C3-M (eight "standard" models from 1 to 1.4GHz, in FSB133 & 200, and one Low Voltage model at 1GHz). 
All were based on the Nehemiah C5P core (therefore, with the full VIA Padlock feature). They differ from the previous Nehemiah C3 EBGAs by a lower voltage : the "standard" C3 EBGAs were at 1.45V, while the standard C3-M were at 1.25V ; the C3 EBGA LP were at 1.25V, while the C3-M LV were at 1.05V .

 

The "special" versions

There were two kinds of "special" versions : the official ones from VIA, and the models rebadged by or for assembly customers.
On the VIA side, they released  PC1000 and PC1500 models, which are respectively only "simple" C3 Samuel 2 800 and C3 Nehemiah 1000.
Their names come from the boards on which they were soldered. The product was the motherboard, not the processor.
These motherboards were created as part of the " VIA PC-1 Initiative " in 2005, a project to provide computers and an Internet connection to populations in developing countries who did not have them.

On the OEM side, there were two types of models : the 1GigaPro and the XP1000 Pro & XP2000 +. 1GigaPros existed with different frequencies, in CPGA and EBGA format and seem to come with PCChips motherboards generally.
EBGA models are also available in 1.1GigaPro, 1.2GigaPro and 1.3GigaPro .
The XP1000 Pro only exists in one model, a C3 Ezra at 733MHz, and the XP2000 + is a Samuel 2 at 800MHz in EBGA format.

 

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History

Models (list)

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