It's been a long time
coming but finally, the Pentium 4 platform has gone
mainstream enough that motherboard manufacturers, like
are building motherboards with the "Power User" and "Tweaker"
in mind. We've seen a bevy of motherboards
recently released for the Pentium 4, with DDR SDRAM
However, RDRAM boards, with a few exceptions, have
been a little bit more straight forward with fewer
bells and whistles than their DDR counterparts.
Abit's fantastic TH7II-RAID for the Socket 478 Pentium
4, made quite a splash when it hit the
HotHardware.com Labs, back in August '01. It has
been an in house favorite ever since.
event RDRAM is new to you, the current spec for RDRAM
memory is labled "PC800". That is to say the
standard clock frequency for the memory bus is a clock
doubled 400MHz speed for a total of 800MHz. It's
a little confusing if you think of the technology
versus DDR, which specifies the speed in the name, in
bandwidth versus clock speed. "PC2100" for
example runs with only a 266MHz (133MHz DDR) clock but
has 2.1GB/sec of bandwidth. In contrast, PC800
RDRAM boasts 3.2GB/sec of bandwidth. Now, we've
been getting rumblings that Intel is readying a
"PC1066" chipset, which has a 533MHz clock doubled
memory clock for 1.066GHz and a 133MHz Quad Pumped
Front Side Bus at 533MHz. We can't wait to get
our hands on a motherboard based on this chipset.
Modding the TH7II-RAID for PC1066, or
close to it
Socket 478 Dream
while we're waiting we thought we would show you a
few tricks that just might get you in that PC1066
ballpark with your current gear! Now, I'll add
in our general disclaimer here. This
modification is certainly NOT for the novice.
As a matter of fact, we had a very skilled PCB
re-work technician help do the de-soldering and
soldering on this project. Her work was
impeccable and we would have never attempted this
modification without her assistance. So in
short, if you try this you are totally on your own.
It can be done very easily with the help of someone
very experienced with a soldering iron and solder
wick. However, you can also toast your board
up relatively easy as well, if you don't know what
you are doing. Oh and guess what? This
procedure totally and completely voids any trace of
warranty you may have on your mother board. Go
then, first we would like to acknowledge one of our
very important sources of information, that being a
gentleman that goes by the nick of
"Raystonn" over at the Vapochill Support Forum.
The folks over there have Pentium 4's overclocking
to 3GHz at PC1066, all day long. Very good
info can be found there on this subject.
what is and isn't capable of PC1066:
Obviously, in the absence of true PC1066 memory on
the retail market, we have to make due with
overclocked PC800 memory and a motherboard that has
the ability to overclock the FSB, like the Abit
TH7II-RAID for example. With a 133MHz FSB and
a 4X multiplier, you'll be hitting 533MHz SDR and
1.066GHz DDR on the RDRAM clocks. However,
there is a good possibility you'll need an
unlocked Pentium 4 for that because, there are very
few chips with standard air cooling, that will hit a
33% overclock, with the exception of the 1.6GHz
variety of the Northwood. This chip is Intel's
new overclocking king. As a result, with our
2.4GHz chip, we had to settle for something a little
less but close to PC1066 performance. When the
new 133MHz Northwoods are available, it will be a
whole new ballgame and the overclocking community
will be having a field day with that CPU, we are
to our RDRAM. Most of today's standard PC800
Samsung RDRAM will handle PC1066 or a 533MHz clock,
as long as you get modules with the lower density
RAM chips on them. These are typically
identified as "double sided" or "16 chip" modules,
if you are looking at 256MB sticks for example.
Check with your retailer but they are fairly readily
available. Take caution though, some of the
newer brand of PC800 RDRAM modules have higher
density chips on board that don't overclock well at
all. In addition, it is best to only load up
two slots on your motherboard. With the
additional loading of a total of 4 RDRAM slots, the
clock jitter causes the heavily overclocked memory
get a little flaky.
The Direct RAMBUS Clock Generator:
this one is the REAL hurdle you have to overcome,
the PC800 DRCG or Direct RAMBUS Clock Generator.
ICS DRCG that came standard on our TH7II-RAID
motherboard, uses a part that is only rated for up
400MHz clock speeds for PC800 specifications.
See if you can spot their location on the board shot
here on the right.
astute folks! They are right below the
HotHardware logo in that shot. Actually, those
are the new
TI DRCGs that we have replaced on the board,
that support a 533MHz clock for the full PC1066
standard. You probably couldn't tell the
difference because they are so small. So, we'll
magnify things for you a bit.
ICS DRCG Clocks
ICS and TI DRCGs
TI DRCGs Closeup
the ICS DRCGs that come standard on this board, will
only handle about 468MHz or 117MHz FSB for
overclocking, without getting very flaky with the
RDRAM. The T.I. DRCGs (far right) will handle 533MHz
or an FSB of 133MHz (or theoretically higher) all day
long, because they are designed to support that speed.
you know that the ICS parts that came standard on our
TH7II-RAID, simply had to go. We're not 100%
sure of this but we're fairly confident that almost
all DRCGs that are designed to the PC800 or PC1066
specification, have the same lead footprint or pin out
with fit, form and functional equivalency. Take
a look below to see the handy-work of our friend the
how hard you look, you can't even see where the solder
forms over the pads on the board to make contact with
the PCB. This is professional PCB re-work folks
and it is the only way to do this modification.
If you don't have the experience with a soldering
iron, don't even think of attempting it. Also,
note the orientation of the chips in this shot.
TI designates the "pin 1" location with the grey
stripe that is silk screened on the top of the part.
This way you know you have the pins facing the right
way and on the right pads of the PCB. If you
flipped that part around, you might cross your power
and ground connections and fry your board but good.
at near PC1066 speeds
If only our
P4 was unlocked or had a 133MHz FSB!
show you the result of our overclocking efforts, with
our new DRCGs installed on the TH7II-RAID.
Again, we were unable to hit the full 133MHz Front
Side Bus speed that would allow us to overclock the
memory to PC1066 levels, due to the fact that our CPU
just wouldn't handle it. However, we were able
to overclock our 2.4GHz Pentium 4 faster than we ever
could before, with standard air cooling. We used
Thermaltake Volcano 478 to cool our CPU
and this little trick on our P4 Northwood, to get
the core voltage up a little higher than the
TH7II-RAID allows, to 1.9V.
CPU @ 3GHz
Multimedia @ 3GHz
Memory @ 1GHz RDRAM
Impressive scores for sure, are shown here in the
Sandra tests. We've never seen the memory
score break 3K until now. We've included the
PCMark memory score here just for reference.
Now, we know you are all wondering, "was it stable".
Frankly no, not over long periods of testing.
However 2.95GHz with an FSB of 123MHz and an RDRAM
clock of 984MHz, certainly was!
this was just a quick look into the world of RDRAM,
DRCGs and perhaps a glimpse of what PC1066 will
bring to the Pentium 4. Stay tuned to
HotHardware in the coming months, to see the real
MacCoy when we get official PC1066 modules in house
along with Pentium 4s and motherboards that support
or any other Hot Hardware Article in the PC Hardware