Hello:

Over at Lost Circuits, there is an interesting review the the Venice Athlon 64 focusing on the excellent power and heat characteristics of this new core.

Great find! The only reviews I had seen so far were trying to overclock them as much as possible on Mach IIs, with little regard to heat dissipation.

8.4 W at idle! Hopefully the extra 512 MB cache on the San Diego won't hurt it's power draw too much; the reviewer didn't seem to think it made a huge difference between Newcastle and Clawhammer. My San Diego is coming soon!

It's at odds with the Xbit review - although this looks like a better comparison.

Grrr, I was about to post that when I refresh and see that you've already done that -_-

Anyways, does this mean that the Venice is supperior to the Winchester in every way (don't care pricewise) ? Or is Xbit the more reliable source?

Possibly, if only by a tiny margin. If you already own a Winny, unless you can sell it for a good bit of money (not likely now that Venice is available) it's probably not worth it to upgrade. If you're still using a 130-nm A64 or something older, it's quite worth it.

EDIT:

Don't forget too that the XBit article was comparing what was basically a first-week Venice to a very mature late-week Winny....perhaps if they had used one of their first Winchester engineering samples they would have gotten much different results.

im building a new system, and had intended on using the winchester 3000, would upgrading to the venice be worth it? as in thermal performance/price?

sorry, this might not be the right place to post that question

Well, I don't got a Winny or any A64... got a very crappy comp atm which I won't even bother giving the specs of

Getting a new rig very soon though and considering that the Venice is almost available at my local stores I was wondering if it truly is superior in every way. Mostly concerning temps & power consumption As far as CPU power goes, the winnie has more then enough of that (for my needs).

i don't like it, those numbers look too low. is it a written law that all cpu power is delivered from the aux connector? i know some a64 setups work fine (albiet sub-optimally) when it's not connected, so there must be a system in place to draw cpu power from the main atx plug instead of the aux.

I mentioned this on slashdot and someone replied saying the device used was not accurate. Check this out http://slashdot.org/comments.pl?sid=148112&cid=12412655

Anyway its about the same as winchester.

I thought about that too, but then again, the numbers for the other CPUs look fairly accurate. The drop in power usage when going to 90nm is nothing short of amazing.

Another thing to think about is that it would almost be too easy of an error if he actually missed something like that. It should be the first thing to investigate thoroughly.

They did do go through the probe three times. While that doesn't help the %error of the measurement, it does help the floor. Effectively, they can measure down to 0.8A through the 12V, which is down to about 10W. As to the %error, that would likely be the same across all the CPUs, so comparisons would still be meaningful.

The single sample is a more serious issue, especially since some other single sample tests have gone the other way (Venice consuming more power than Winchester). Eventually as more tests come out we'll get a clearer picture. In the mean time, I am assuming that Winchester and Venice are fairly comparable from a power perspective. Maybe Venice will overclock and/or underclock better, but there are significant sample-to-sample differences for overclocking and undervolting within Winchester, so I think it is too early to tell.

Old news!

is it possible to make any statements about venice's undervolting potential, versus winchester.

if we assume that winnie and venice at teh same frequency and vcore puts out the same amount of heat/power consumption (say b/c the sample size of 1 is too small) but venice can undervolt more than winnie, then i would say venice is a winner.

Hello:

Here's a better place to have this thread:

http://forums.silentpcreview.com/viewtopic.php?t=21743

Venice almost seems to perform too well, raping even the 1mb 2.4GHz Claw in most every test (not just the ones involving power consumption). But who knows, maybe this new revision is just that good. I personally can't wait to get my hands on a San Diego.

The number are lower than the 35watts TDP of the new Turion. If these were normal, the Turion wouldn't make any sense. I'm sceptical ... though if correct, these Venices would be a killer.

Bye egghat.

I never said it was

Well, they do run at the same default voltage as the Turion 35W. Also, it's not unusual that actual power consumption is lower than the TDP. As mentioned in the article, TDP is probably a simulated number for when loading every single transistor on the chip.

Aren't AMD TDP's actually kind of future-proofed, so that they don't have to change the tdp when introducing new clockspeeds of the same core.

According to AMD, "Thermal Design Power (TDP) is measured under the conditions of Tcase Max, IDD Max, and VDD=VID_VDD, and include all power dissipated on-die from VDD, VDDIO, VLDT, VTT, and VDDA."

In other words, AMDs TDP numbers reflect worst-case scenarios, and should be taken with a grain of salt. It is unlikely that in a desktop environment, one will be running the processor at it max temp, where it draws the most power. Hence the real-life power consumption numbers are much lower.

It also explains why the TDP numbers for Turion seem so high. Tcase Max for the mobiles in somewhere in the range of 95*C, compared to 65-70*C (something like that) for the desktop Venice/San Diego. So Turion is tested under much more demanding conditions. In a desktop environment they would probably draw much less power than even Venice/San Diego, although they probably even out in a mobile environment where spaces are cramped and operating temps are higher.

Doesn't the mobo VRM's efficiency vary with load?

Another review of the Venice 3800+ from neoseeker.com

Not much of a heat/wattage comparison although it does mention that the vcore needed for the Venice is lower compared to the Winchester.

Im guessing that the Venice is preferable... if it is in stock by the time I get the rest of my comp together Im getting it although I wouldn't see any need to upgrade from the Winchester to Venice... the difference isn't that amazing.

If the Venices run on the same voltage as the Turion, the 30 watt measurement would be quite plausible. Strange, that xbitlabs measured something completly different.

But all I know is that the core voltage of the Venices is 1.40 volts (e.g. here), which is way higher than Turion's stock voltage (1.1 volt IIRC).

Bye egghat

A64E: 1.4 V or 1.35 V, both available.

T64 ML: 1.35 V
T64 MT: 1.2 V

Lostcircuits have reviewed the AMD Athlon 64 X2 4800+. It looks like going from 130 nm to X2 is not a big deal (63 W), but the X2 doesn't run at 100 % load with only one Prime95 running.... They get 86 W when running two instances of Prime95.

A Finnish overclocker Sampsa Kurri has tested A64 X2 4800+ with S&M 1.6beta (the strongest heat generator, more efficient than CPUBurn or Prime95 or anything else known to man).

A64 X4800+ results
==============
CPU internal probe: 63 C
Underside of the sink (thermal probe): 45,4C
System power consumption (kill-a-watt reading): 236W

As a comparison, Intel Pentium Extreme Edition 840 settled the temps at the following (same loading with S&M):

Intel Pentium EE 840 results
====================
CPU internal probe: 91 C
Underside of the heatsink: 64,2 C
System power consumption (kill-a-watt reading): 315W
(system crahed after 8 minutes of running with the stock Intel cooler)

Above measure were at stock speeds / voltages.

Note, S&M does load the CPU more than anything out there (test it yourself, if you don't belive me). It can easily reach temp +5C higher or more compared to prime95 (any test) and even better than CPUBurn. You need to run it with safe mode disabled and using 100% load setting (both are internal options in S&M).

To me it looks like X2 4800+ can still be cooled although stretching it (in a silent air cooling scenario). P4 840 again... no.

Looking on this review and assuming their measurements are correct, my Venice 3200+ running at 1.1v consumes 15.4W at load according to CPU Power. With no cooling at all other than the passive heatsink it takes about two minutes to rise a degree, so it can't be producing much heat. I'm pleasantly surprised by it and can't wait for ASUS to answer my mail and tell me how to go below 1.1v

I don't know how well P-M can undervolt, but this could be a faster and/or cheaper solution.

wow! you sure thats an accurate reading?

Those results put the 4800X2 at lower wattage and temps than my 3.4 gig northwood P4 wich means that a dozen or so good quality heatsinks on the market can cool it very quietly It looks to be a good way for me to go actually if I can rake the $$$

The Venice should be superior to Winchester, at least on paper. Apart from adding SSE3-instructions the other mayor news with Venice is that it employs stretched silicon, which is the same method that Intel uses in the Prescotts (don't let that scare you away, though). I believe IBM and AMD claims that their method to stretch silicon offers 24 % faster transistor switching at the same amount of power, which I believe should translate into an equally larger performance/watt-increase.

Actually I believe the lostcircuits-article comments on this and their readings seem to confirm that the Venice actually does offer this MHz/watt advantage.

This said it's probably possible that these early Venice-yields aren't consistently superior to Winchester. But at least I'm not in doubt about which processor I'll use when I build a rig in August, I think Venice will have matured by then.