Hi all - I am building a HTPC and need help deciding between these 2 video cards. The (much) cheaper card has twice the memory (512) but it is GDDR2 and runs slower. The more expensive card has half the memory but runs much faster.

This box will never be used for gaming - besides every day use (hooked up to a 1080p display), it will be used mainly for video content (including streamed HD).

What is more important for this use - memory speed or size?

Just trying to decide if it is worth paying the much higher price for half the memory, but quicker.


ASUS EN8500GT SILENT/HTP/512M GeForce 8500GT 512MB 128-bit GDDR2 PCI Express x16 HDCP Ready Video Card ($92.99)

GPU GeForce 8500GT
Core clock 459MHz
Memory Clock 800MHz
Memory Size 512MB
Memory Type GDDR2

OR

ASUS EN8600GTS SILENT/HTDP/256M GeForce 8600GTS 256MB 128-bit GDDR3 PCI Express x16 HDCP Ready SLI Supported Video Card ($174.99)

GeForce 8600GTS
Core clock 675MHz
Memory Clock 2GHz (1000MHz DDR3)
Memory Size 256MB
Memory Type GDDR3

If you are sure you won't be gaming, do you really need an 8500/8600? The common recommendation for HD on the mythtv mailing list seems to be nothing more than a 6200. I have a fanless 7600gs (using component-out 1080i) that works just fine but is probably overkill. I don't think a "bigger" video card does much good once you have one that is basically HD capable, it's likely to be a very long time before all the extra pixel shaders/what have you are actually used by linux drivers (or needed for tv-watching, vs gaming).

I'm just saying.

I am going through a similar decision process though am thinking of the 7x series. I definitely want to support 1080p though I am currently using a 1366X768 display. The following things are a concern to me:

Linux support. recent spec releases removes some of my worries though that's not likely to matter in the short run. Guess I'll just take my chances.

noise vs heat. Quiet is good. Fanless makes sense but the case I am thinking of (Zalman 160) isn't known for good airflow. Unfortunately, most fanless video cards seem to rely on good airflow. So, I punt fanless but eat it on dbs or add extra airflow to the case and eat it on dbs. I'm not sure which is the lowest noise solution here because the case is aluminum. My gut says add to the case since it helps with the more general heat problems.

Anyone have specific card suggestions with those issues in mind?

Do any of the 8xxx cards have Linux drivers that support basic functionality for HD? I've heard everything from "only 5300/5200 and below have Linux drivers", but people like h_a_h_3 apparently are successfully using 7600GS with Myth. h_a_h_3, do you know if 7600GS works with HDMI/DVI I/O and are you using a Linux driver designed for it, or an older 6xxx driver that happens to work with it? There's also 8400GS based cards like the fanless Gigabyte GV-NX84G256H that has on-board hardware HD processing just like the 8500 cards, but no drivers support the on-board hardware HD yet. This 8400GS card is only $60. At the price level of about $50 and below, the price differentials between lower level cards are negligible, so I wouldn't mind overkill with currently unsupported onboard HD and such as long as the card works with Myth.

huggybear, I definitely wouldn't spend close to $200 on a card if you can get similar performance out of a $100, or better yet $50-60 card.

My 7600gs card has, in addition to the component-out dongle that I'm using, a DVI port and a VGA port. Electrically, DVI and HDMI are equivalent - you can buy simple adapters. It's quite unlikely that HDCP over either DVI or HDMI is going to be used in a Linux system, if you think about how HDCP gets required (content provider strong-arms software/hardware vendors) - content providers already view Linux users as almost pirates since there's no chance of getting any content-protection scheme for Linux introduced (whew!).

As far as drivers, I am using Nvidia's binary blob driver 1.0-9746 that I downloaded from their website. It's a one-size-fits all package; newer versions add support for later cards but this one works fine for me.

Linux driver support for the "hardware HD processing" like PureVideo or whatever is something I wouldn't expect to see any time soon, but it's not really needed with appropriate CPU selection (aka something dual core). I had a 4600 x2 (65w) that I just "downgraded" to a 45w BE2350 (equivalent to 4100 x2 or so) and it still plays 1080i just fine.

I think that any modern video card has more than enough memory for HTPC usage. But, I'm wondering exactly how much can/would be used in a worst case (best case?) scenario.

For simple display purposes, the memory calculation is straightforward: X pixels * Y pixels * C Bytes Color depth (I'll use 4 bytes/32bits as a worst case. I think most cards would use 3 bytes/24bits.)

720p, using 4 bytes for color: 1280x720x4 = 3,686,400 Bytes = 3.6MB
1080p: 1920 X 1080 X 4 = 8,294,400 = 8.1MB
1200p: 1920x1200x4 = 9,216,000 = 9MB

Not much memory needed for basic display.. Then, the actual video would be displayed using a video overlay, or a texture, depending on the card. So, the memory usage would double.

Anything beyond that? Would using 3D textures, like recent NVidia cards, rather than an overlay use more memory? How about things like de-interlacing? Would it need to keep multiple fields around for that processing?


In any case, it seems like anything beyond 64MB (or even 32MB, which you can't find for sale anymore) would be unused for pure HTPC usage.

Even HTPC interfaces seem to be using 3D/OpenGL for their UI. So, a bit of headroom in video memory is a nice precaution. But, I certainly wouldn't waste much money on more video RAM.

Am I missing anything?

You might want one of these cards for the bloatware that is Vista, but using one to display HD on a Myth box is like smashing an ant with a hammer. Onboard 6xxx or a cheapo 6600 is perfectly fine for any HD on a properly configured system.

I have an onboard Nvidia 6150 in one system and an agp 6200 in a test system. Both work great with HD video and XvMC. The 6150 is driving a 1080p LCD panel at 1920x1080 with no problems.

I have a 6150 and a PCIe 6200 driving my HDTVs just fine. The 6150 took some tweaking through DVI, the 6200 didn't take much going through VGA. not using XvMC (processors are x2 3800 and x2 4200). Heck, my old AGP 440MX is driving my 20" monitor at a high def resolution just fine with mythtv and a P4 2.6Ghz hyperthreading - without XvMC.

I'm using a Gigabyte 8400GS with MythTV. I was looking at the 7300 and 8400GS series. That 8400GS is fanless and I like that from a noise perspective. It also runs relatively cool. I live in a hot climate and room temp may climb to 90-91 F during the day with the AC off, but I've never had any overheating problems - even in an glass enclosed Sony TV stand.

I'm currently using component out to an old Sony Wega 32" SDTV. When I get a HDTV, I'll use DVI to HDMI. The newest NVidia Linux drivers are fine and very stable (in Ubuntu at least), but the overscan adjustment doesn't work like it did in the older drivers. For what it's worth, I went from an ancient MX400 to the 8400GS without any problems.

Good to hear that nVidia's driver will work for any card up to the latest ones.

I didn't even consider on-board 6xxx. That would save me a PCI slot as I'll only have 4 expansion slots with a MicroATX case/board for my box. Would that run cooler than no on-board video plus a card setup? Also $50-60 savings is a plus. :) Do any Core2Duo boards have on-board 6xxx video, or is that only with AMD?

I'm sure they make a 61xx version for C2D, but you don't need the little extra speed or the large extra expense of the C2D CPU.

I'm choosing C2D over AMD because of the heat and power savings. It's going to be a front/back end in a MicroATX box (probably the Antec NSK2400) that will sit in my AV stand under the TV. Heat/fan=quietness is the main concern, and hopefully the power savings will offset the cost a bit over time.

I didn't see any C2D/LGA775 mobos with nvidia 6xxx onboard in a quick scan of newegg. BTW, I just replaced my mythbox's 65w x2 4600 (was ~$350 last year) with a 45w x2 BE-2350 ($95) - I'm now using the boxed cooler vs fancy heatpipe thingy before, and can't hear it at all.