AMD’s architecture hasn’t generally shown a large gain from increasing CU count between top-tier and second-to-top cards. The Fury and Fury X, for instance, could be made to match with an overclock on the lower-tiered card. Additional gains on the higher-tiered card often amount from the increased power limit and clock, not from a straight shader increase. We’re putting that knowledge to the test on Vega architecture, equalizing the Vega 56 & Vega 64 clocks (and 945MHz HBM2 clocks) to determine how much of a difference emerges from the 4096 shaders on V64 to 3584 shaders on V56. Purely counting shaders, that’s a 14% increase to V64, but like most performance metrics, that won’t result in a linear performance increase.
We were able to crush Vega 64’s performance with our heavily modded Vega 56 card, using powerplay tables and liquid to jump to 1742MHz clock speeds. That's with modding, though, and isn't out-of-box performance -- it also doesn't give us any indication as to shader differences. Going less crazy about overclocking and limiting clocks to matched speeds, we can reveal the shader count difference.
While traveling, the major story that unfolded – and then folded – pertained to the alleged unlocking of Vega 56 shaders, permitting the cards to turn into a “Vega 58” or “Vega 57,” depending. This ultimately was due to a GPU-Z reporting bug, and users claiming increases in performance hadn’t normalized for the clock change or higher power budget. Still, the BIOS flash will modify the DPM tables to adjust for higher clocks and permit greater HBM2 voltage to the memory. Of these changes, the latter is the only real, relevant change – clocks can be manually increased on V56, and the core voltage remains the same after a flash. Powerplay tables can be used to bypass BIOS power limits on V56, though a flash to V64 BIOS permits higher power budget.
Even with all this, it’s still impossible (presently) to flash a modified, custom BIOS onto Vega. We tried this upon review of Vega 56, finding that the card was locked-down to prevent modding. This uses an on-die security coprocessor, relegating our efforts to powerplay tables. Those powerplay tables did ultimately prove successful, as we recently published.
Everyone talks game about how they don’t care about power consumption. We took that comment to the extreme, using a registry hack to give Vega 56 enough extra power to kill the card, if we wanted, and a Floe 360mm CLC to keep temperatures low enough that GPU diode reporting inaccuracies emerge. “I don’t care about power consumption, I just want performance” is now met with that – 100% more power and an overclock to 1742MHz core. We've got room to do 200% power, but things would start popping at that point. The Vega 56 Hybrid mod is our most modded version of the Hybrid series to date, and leverages powerplay table registry changes to provide that additional power headroom. This is an alternative to BIOS flashing, which is limited to signed drivers (like V64 on V56, though we had issues flashing V64L onto V56). Last we attempted it, a modified BIOS did not work. Powerplay tables do, though, and mean that we can modify power target to surpass V56’s artificial power limitation.
The limitation on power provisioned to the V56 core is, we believe, fully to prevent V56 from too easily outmatching V64 in performance. The card’s BIOS won’t allow greater than 300-308W down the PCIe cables natively, even though official BIOS versions for V64 cards can support 350~360W. The VRM itself easily sustains 360W, and we’ve tested it as handling 406W without a FET popping. 400W is probably pushing what’s reasonable, but to limit V56 to ~300W, when an additional 60W is fully within the capabilities of the VRM & GPU, is a means to cap V56 performance to a point of not competing with V64.
We fixed that.
AMD’s CU scaling has never been that impacting to performance – clock speed closes most gaps with AMD hardware. Even without the extra shaders of V64, we can outperform V64’s stock performance, and we’ll soon find out how we do versus V64’s overclocked performance. That’ll have to wait until after PAX, but it’s something we’re hoping to further study.
Vega’s partnership with the Samsung CF791, prior to the card even launching, was met with unrelenting criticism of the monitor’s placement in bundles. Consumer reports on the monitor mention flickering with Ultimate Engine as far back as January, now leveraged as a counter to the CF791’s inclusion in AMD’s bundle. All these consumer reports and complaints largely hinged on Polaris or Fiji products, not Vega (which didn’t exist yet), so we thought it’d be worth a revisit with the bundled card. Besides, if it’s the bundle of the CF791 with Vega that caused the resurgence in flickering concerns, it seems that we should test the CF791 with Vega. That’s the most relevant comparison.
And so we did: Using Vega 56, Vega: FE, and an RX 580 Gaming X (Polaris refresh), we tested Samsung’s CF791 34” UltraWide display, running through permutations of FreeSync. Some such permutations include “Standard Engine” (OSD), “Ultimate Engine” (OSD), and simple on/off toggles (drivers + OSD).
This is just a quick PSA.
We shot an off-the-cuff video about software misreporting Vega’s frequency, to the extent that a “1980MHz overclock” is possible under the misreported conditions. The entire point of the video was to bring awareness to a bug in either software or drivers – not to point blame at AMD – explicitly to ensure consumers understand that the numbers may be inaccurate. Some reviews even cited overclocks of “1980MHz,” but overlooked the fact that scaling ceases around the threshold where the reporting bugs out.
Following questions regarding the alleged expiry of MDF and rebates pertaining to Vega’s launch, AMD responded to GN’s inquiries about pricing allegations with a form statement. We attempted to engage in further conversation, but received replies of limited usefulness as the discussion fell into the inevitable “I’m not allowed to discuss this” territory.
Regardless, if you’ve seen the story, AMD’s official statement on Vega price increases is as follows:
As exciting as it is to see “+242% power offset” in overclocking tools, it’s equally deflating to see that offset only partly work. It does, though, and so we’ve minimally managed to increase our overclocking headroom from the stock +50% offset. The liquid cooler helps, considering we attached a 360mm radiator, two Corsair 120mm maglev fans, a Noctua NF-F12 fan, and a fourth fan for VRM cooling. Individual heatsinks were also added to hotter VRM components, leaving two sets unsinked, but cooled heavily with direct airflow.
This mod is our coolest-running hybrid mod yet, with large thanks to the 360mm radiator. There’s reason for that, too – we’re now able to push peak power of about 370-380W through the card, up from our previous limitation of ~308W. We were gunning for 400W, but it’s just not happening right now. We’re still working on BIOS mods and powerplay table mods.
Following the initial rumors stemming from an Overclockers.co.uk post about Vega price soon changing, multiple AIB partners reached out to GamersNexus – and vice versa – to discuss the truth of the content. The post by Gibbo of Overclockers suggested that launch rebates and MDF would be expiring from AMD for Vega, which would drive pricing upward as retailers scramble to make a profit on the new GPU. Launch pricing of Vega 64 was supposed to be $500, but quickly shot to $600 USD in the wake of immediate inventory selling out. This is also why the packs exist – it enables AMD to “lower” the pricing of Vega by making return on other components.
In speaking with different sources from different companies that work with AMD, GamersNexus learned that “Gibbo is right” regarding the AMD rebate expiry and subsequent price jump. AMD purportedly provided the top retailers and etailers with a $499 price on Vega 64, coupling sale of the card with a rebate to reduce spend by retailers, and therefore use leverage to force the lower price. The $100 rebate from AMD is already expiring, hence the price jump by retailers who need return. Rebates were included as a means to encourage retailers to try to sell at the lower $499 price. With those expiring, leverage is gone and retailers/etailers return to their own price structure, as margins are exceptionally low on this product.
Tearing open the RX Vega 56 card revealed more of what we expected: A Vega Frontier Edition card, which is the same as Vega 64, which is the same as Vega 56. It seems as if AMD took the same PCB & VRM run and increased volume to apply to all these cards, thereby ensuring MOQ is met and theoretically lowering cost for all devices combined. That said, the price also increases in unnecessary ways for the likes of Vega 56, which has one of the most overkill VRMs a card of its ilk possibly could -- especially given the native current and power constraints enforced by BIOS. That said, we're working on power tables mods to bypass these constraints, despite the alleged Secure Boot compliance by AMD.
We posted a tear-down of the card earlier today, though it is much the same as the Vega: Frontier Edition -- and by "much the same," we mean "exactly the same." Though, to be fair, V56 does lack the TR6 & TR5 screws of FE.
Here's the tear-down:
This week’s hardware news recap goes over some follow-up AMD coverage, closes the storyline on Corsair’s partial acquisition, and talks new products and industry news. We open with AMD RX Vega mining confirmations and talk about the “packs” – AMD’s discount bundling supposed to help get cards into the hands of gamers.
The RX Vega discussion is mostly to confirm an industry rumor: We’ve received reports from contacts at AIB partners that RX Vega will be capable of mining at 70MH/s, which is something around double current RX 580 numbers. This will lead to more limited supply of RX Vega cards, we’d suspect, but AMD’s been trying to plan for this with their “bundle packs” – purchasers can spend an extra $100 to get discounts. Unfortunately, nothing says those discounts must be spent, and an extra $100 isn’t going to stop miners who are used to paying 2x prices, anyway.
Show notes below.
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